Please describe the problem:
When creating a new SSH key, under "advanced" the user has the option to select either RSA or DSA key types using a pull down list, and the key length using a spin box. The spin box's default value is 2048 and it isn't bound to the type selection, so when the user chooses the DSA type that cannot have 2048 bit key length, the spin box doesn't change.

Steps to reproduce:
1. Under "First time options", click "New" next to "Generate a new key of your own"
2. Choose SSH key
3. In the next dialog, open the "Advanced" section and select "DSA" from the "Encryption Type" drop down list.
4. Hit "Just Create Key" or "Create and Setup"


Actual results:
An error dialog pops up to notify that the DSA type cannot be used with 2048 bit key length, and 1024 bit key length must be used. Hittin "OK" on that error dismisses the dialog entirely and the user has to start over (which is a bit of an annoyance if the user typed something interesting into the key's comment box).

Expected results:
Key creation should succeed even if the user only modified the encryption type selection and not the bit length. This can be achieved by several methods - one way is to make sure that when DSA is selected, the key length spin box's value automatically changes to 1024.

Does this happen every time?
Yes

Other information:
I think the "advanced" part of the interface could use some usability tweaking. Specifically, the drop down list is not the best method to show only two short options, and it can possibly be changed to a radio button - this makes the selection so much easier as the user can see immediately all the options available.

Secondly, the use of a spin box for the key length is also not the best of choices as there is only a small discrete number of valid options. A drop down list in this case makes sense, but depending on the number of available options a radio button set or a slider are probably better choices (I lean towards a slider as its better suited to choose between a number of numeric options on a continuum, and as the number of options increases it can pack better then a radio button set).

More importantly - as for DSA keys 1024 bit is the only valid key length, when the user chooses "DSA" for the encryption type the key length control should immediately change to 1024 bit and be disabled - this will allow the user to understand that this is the only valid key length, with out the use of an error dialog and without forcing the user to back track.