I've noticed a few significant issues with Network Manager on GNOME 3.2, when connecting to WiFi networks that require password (e.g. WPA, EAP). Trying to find existing bug reports, I've found quite a mess: multiple bug reports, both downstream (Debian, Ubuntu, Fedora) and upstream (GNOME bugzilla).
I suspect many of these bugs are related to the same root cause (or max. 2-3 root causes). In order to try and make sense of this, I tried to categorize the bugs I've found. I hope it'll help to gather more info to resolve the bugs, and reject dups.
- NM (gnome applet?) forgets passwords:
- GNOME Bugzilla: , , 
- Debian BTS: , 
- Ubuntu BTS: 
- Mint forum post with a workaround
- NM takes too long to re-connect after resume (possibly problem in popping up the enter-password dialog box):
- NM-gnome double password dialog box case:
I'll try to update this post when new info arrives, please add your comments.
Generally speaking, I think that FOSS community lacks some "dirty-work" QA workforce for bug scrubbing, such as what I'm trying to do here. I don't even know how to name this non-coding activity. Thoughts?
Update1: This Linux Mint forum post suggests that only the applet "forgets" passwords.