Here are a few other issues I've come across while using the most recent snapshots. Some may be specific to my setup but some may be bugs. I'll provide any extra information as required. But I hope these observations are of some use.

1. Autosave seems not to be working properly. It just doesn't kick in at all. The last time it happened terminal gave the following error:
Writing tags in /home/sheamus/.config/gmusicbrowser/gmbrc ...
*** unhandled exception in callback:
***   Can't use string ("wombalton: Two Panes") as a HASH ref while "strict refs" in use at /usr/bin/gmusicbrowser line 1663.
***  ignoring at /usr/bin/gmusicbrowser line 1072.

I don't know it this is related to the general behaviour of not saving. If I try to save manually there is no problem. Also, there are times when autosave works without a problem which leads me to believe it may have something to do with my setup.

2. Crashing during autosave. When autosave is working properly gmb will crash with a segmentation fault if the song is changing during autosave.
3. Crashing during check for updated/changed tracks, check for new tracks. Again if there is a song change during either of these processes gmb will crash.
4. Not saving playlists. If I am listening to a filter with the queue set up to autofill according to last played, date etc. then these settings are not being saved when I shut down. The queue remains intact but that is all, it reverts back to normal mode, with no filter selected and no play order. The only exception is if I am using weighted random, the weighted random setting is kept.

I hope these are useful, or they may point to one common problem. I am using a reasonably fresh (less than two weeks old) install of Ubuntu Karmic although the same problems were happening with Jaunty.

1) there was a bug that caused saving problems with layouts that have ":" in their name. I fixed it some time ago in git, I should have released a 1.1.4 sooner, I'll do it soon, maybe later today.

2) and 3) yes, that happen when the gapless option is on. The gapless option use a new feature of gstreamer "playbin2" that replace "playbin", which cause these crashes. I still don't know if the crashes come from my code, from gstreamer or from the perl bindings for gstreamer.

4) I'll take a look at this, I'll reply later.

4) Not saving playlists.
It works for me, did you check the "remember filter" option in the "Misc." tab ?
The autofill mode is not saved because I never thought about saving it, but I will fix it so that it is saved if the "remember filter" option is on. Or maybe I should add a "remember queue" option ?