Version details: 1.4.1
Distribution/Version: Red Hat 9.0

Preparation:
a. use Exchange connector to access Exchange calender
b. look at a meeting invitation email, enter it to calender if necessary

Restart Evolution (might not be necessary),
have the message preview open:

1. look at the meeting invitation email: it is said to be found in calender
2. switch to a normal email (I switched to a different folder for that)
3. switch back to the invitation email

Evolution exchange connector dies, error is:
libedata-cal-ERROR **: file e-cal-backend.c: line 294 (e_cal_backend_finalize):
assertion failed: (priv->clients == NULL)
aborting...

I investigated this in a debugger. What I found is that
in 1., the function impl_CalFactory_getCal() from e-data-cal-factory.c
creates the backend for the first time and adds it to the hash with
the key "exchange://pohly%40GER;auth=Basic@email.intel.com/;personal/Calendar:4".

Then in 3. lookup_backend() searches the hash with a truncated
url string "exchange://pohly@GER;auth=Basic@email.intel.com/" which yields
no result, so impl_CalFactory_getCal() creates another instance.
While adding it, the hash code automatically deletes the old instance and
that complains with the assert above (presumably because it is still in use).

I used garnome-2.12.1 to compile from source. Here is a patch which fixes
the problem. It does no error checking and probably creating the key should
be moved into a separate function to avoid code duplication.

*** evolution-data-server-1.4.1/calendar/libedata-cal/e-data-cal-factory.c.orig
2005-10-12 14:36:05.000000000 +0200
--- evolution-data-server-1.4.1/calendar/libedata-cal/e-data-cal-factory.c     
2005-10-12 14:39:30.000000000 +0200
***************
*** 238,245 ****
                        goto cleanup;
                }
  
!               /* Track the backend */
!               g_hash_table_insert (priv->backends, g_strdup (uri_type_string),
backend);
  
                g_signal_connect (G_OBJECT (backend), "last_client_gone",
                                  G_CALLBACK (backend_last_client_gone_cb),
--- 238,256 ----
                        goto cleanup;
                }
  
!               /* Track the backend, using the same key as in lookup_backend() */
!                 {
!                     EUri *uri;
!                     char *key;
!                     uri = e_uri_new (uri_type_string);
!                     if (!uri) {
!                         /* error handling? */
!                     }
!                     key = e_uri_to_string (uri, FALSE);
!                     e_uri_free (uri);
! 
!                     g_hash_table_insert (priv->backends, key, backend);
!                 }
  
                g_signal_connect (G_OBJECT (backend), "last_client_gone",
                                  G_CALLBACK (backend_last_client_gone_cb),