A handful of users have been reporting force closes and bugginess when running reddit is fun and CyanogenMod and apps2sd. Unfortunately I don't use either, so I can't reproduce the bugs.
I wonder if any Android developers who do use these mods would mind helping debug this issue?
(follow the issue at http://github.com/talklittle/reddit-is-fun/issues/#issue/13)
EDIT: Ok, I looked at xda-developers forum and see there's this script, switchrom.sh to make it easier to switch between different ROMs. Well, I guess I'll try it out then.
Used this recovery image by JesusFreke to do Nandroid backup before anything else. Then replaced with Cyanogen's 1.4 after I installed CyanogenMod 126.96.36.199. (probably could have skipped using the first recovery image at all... oh well)
Took a break and donated 5 bucks to Cyanogen's beer fund :)
Then backed up sd card contents, and following directions here to setup partitions for apps2sd (which is automatic in Cyanogen rom after doing partitioning)
EDIT2: Yes, I have now indeed encountered force closes that I didn't encounter with stock rom. They mostly happen when rotating the screen. Happened again when rotating screen with login dialog onscreen. Also I get a weird bug where it doesn't load the threads list correctly the first time, and I have to refresh to get anything to show up.
EDIT3: FIXED!!! I had a bunch of errors caused by things like weird Android behavior, trying to run onPrepareDialog for every possible Dialog whenever you rotate the screen or return from another Activity, leading to NullPointerExceptions. Some other things too, like having to setup the DefaultHttpClient to be multithreaded (found examples on apache.org HttpClient 4.0 samples). So grab version 0.7.11, and CyanogenMod too :)