When I run gossip 0.27, I get:

/home/sam/.gnome2/Gossip/accounts.xml:4: element account: validity error : Element account content does not follow the DTD, expecting (name , id , resource? , password? , server? , port? , auto_connect? , use_ssl? , use_proxy?), got (name auto_connect use_proxy parameter parameter parameter parameter )
/home/sam/.gnome2/Gossip/accounts.xml:4: element account: validity error : No declaration for attribute type of element account
/home/sam/.gnome2/Gossip/accounts.xml:8: element parameter: validity error : No declaration for element parameter
/home/sam/.gnome2/Gossip/accounts.xml:8: element parameter: validity error : No declaration for attribute name of element parameter
/home/sam/.gnome2/Gossip/accounts.xml:8: element parameter: validity error : No declaration for attribute type of element parameter
/home/sam/.gnome2/Gossip/accounts.xml:9: element parameter: validity error : No declaration for element parameter
/home/sam/.gnome2/Gossip/accounts.xml:9: element parameter: validity error : No declaration for attribute name of element parameter
/home/sam/.gnome2/Gossip/accounts.xml:9: element parameter: validity error : No declaration for attribute type of element parameter
/home/sam/.gnome2/Gossip/accounts.xml:10: element parameter: validity error : No declaration for element parameter
/home/sam/.gnome2/Gossip/accounts.xml:10: element parameter: validity error : No declaration for attribute name of element parameter
/home/sam/.gnome2/Gossip/accounts.xml:10: element parameter: validity error : No declaration for attribute type of element parameter
/home/sam/.gnome2/Gossip/accounts.xml:11: element parameter: validity error : No declaration for element parameter
/home/sam/.gnome2/Gossip/accounts.xml:11: element parameter: validity error : No declaration for attribute name of element parameter
/home/sam/.gnome2/Gossip/accounts.xml:11: element parameter: validity error : No declaration for attribute type of element parameter

** (gossip:31134): WARNING **: Failed to validate file:'/home/sam/.gnome2/Gossip/accounts.xml'

My accounts file:

<?xml version="1.0" encoding="utf-8"?>
<accounts>
  <default>robots</default>
  <account type="Jabber">
    <name>robots</name>
    <auto_connect>yes</auto_connect>
    <use_proxy>no</use_proxy>
    <parameter name="account" type="s">sam@robots.org.uk</parameter>
    <parameter name="password" type="s">xyzzy</parameter>
    <parameter name="resource" type="s">home</parameter>
    <parameter name="server" type="s">robots.org.uk</parameter>
  </account>
</accounts>

I also experienced the same issue, but in my case it was when upgrading from 0.23 to 0.26.

All files are still under ~/.gnome2/Gossip, but gossip seems to ignore them.

Are the settings now stored somewhere else?

And here's the output of the gossip invokation:

/home/dpm/.gnome2/Gossip/accounts.xml:4: element account: validity error : No declaration for attribute cmgr_name of element account
/home/dpm/.gnome2/Gossip/accounts.xml:4: element account: validity error : No declaration for attribute protocol of element account
/home/dpm/.gnome2/Gossip/accounts.xml:15: element account: validity error : No declaration for attribute cmgr_name of element account
/home/dpm/.gnome2/Gossip/accounts.xml:15: element account: validity error : No declaration for attribute protocol of element account
/home/dpm/.gnome2/Gossip/accounts.xml:26: element account: validity error : No declaration for attribute cmgr_name of element account
/home/dpm/.gnome2/Gossip/accounts.xml:26: element account: validity error : No declaration for attribute protocol of element account
/home/dpm/.gnome2/Gossip/accounts.xml:37: element account: validity error : No declaration for attribute cmgr_name of element account
/home/dpm/.gnome2/Gossip/accounts.xml:37: element account: validity error : No declaration for attribute protocol of element account

** (gossip:6067): WARNING **: Failed to validate file:'/home/dpm/.gnome2/Gossip/accounts.xml'

** (gossip:6067): WARNING **: No GossipAccount found by name:'David-MSN'

** (gossip:6067): WARNING **: No GossipAccount found by name:'David-jabber'

** (gossip:6067): WARNING **: No GossipAccount found by name:'David-gmail'

** (gossip:6067): WARNING **: No GossipAccount found by name:'David-gmx'

** (gossip:6067): WARNING **: No GossipAccount found by name:'David-msn'

(gossip:6067): GdkPixbuf-CRITICAL **: gdk_pixbuf_scale_simple: assertion `dest_width > 0' failed

(gossip:6067): GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' failed

Apparently the format of the accounts file changed between releases. There's no upgrade path provided. Which sucks.

Here's the old schema:

<?xml version="1.0" encoding="utf-8"?>
<accounts>
  <default>jabber.org</default>
  <account type="Jabber">
    <name>jabber.org</name>
    <auto_connect>yes</auto_connect>
    <use_proxy>no</use_proxy>
    <parameter name="account" type="s">username@jabber.org</parameter>
    <parameter name="password" type="s">**********</parameter>
  </account>
</accounts>

and the new schema:

<?xml version="1.0" encoding="utf-8"?>
<accounts>
  <default>jabber.org</default>
  <account>
    <name>jabber.org</name>
    <id>username@jabber.org</id>
    <resource>Home</resource>
    <!--Password is stored in GNOME Keyring-->
    <server>jabber.org</server>
    <port>5223</port>
    <auto_connect>yes</auto_connect>
    <use_ssl>yes</use_ssl>
    <use_proxy>no</use_proxy>
  </account>
</accounts>

There should be a way to do a quick xslt to convert from one to the other, but since the files aren't versioned, it's probably hard for Gossip to know whether you're using the new or the old at start-up.

This is the old format we used before deciding NOT to use Telepathy.
This bug is quite obsolete now.
Apologies for the inconvenience. Usually we have upgrade paths in place, but sometimes it is missed.
Marking as WONTFIX.