According to reports in the toucharcade.com and macrumors.com comments
List of Apps affected by the
2.1 software update beside number of forum reports: (in order of reports)
> 20 reports
Last.fm: (no audio)
Developer aware, v2.0 update in transit
Zen Pinball: (no graphics white screen)
Developer aware, v2.1 update in transit with improved frame rate, responsiveness, and graphics
Toybot Diaries: (corrupted sound effects)
Developer aware, v1.2 update in transit
10 or more reports
Alli's Jigsaw:(cannot select new image)
Developer aware, update in transit
Asphault 4: (11) (drifting and braking sound effect corrupted, freezes)
5 or more reports
Splash ID: (8) (?keyboard no longer automatically appears in login screen?/works intermittently for some)
Developer aware, update in transit
2 or more reports
Jeyo Mobile Extender: (nonfunctional, connects ok but no transfer of messages to outlook)
Developer aware, currently software was rendered incompatible with iPhone 2.1 Update
Brain Tuner: (crashes, appears to function after reinstall though)
Reinstall fixes issue
My Weather: (fails to launch)
Reinstall fixes issue
Text Guru: (crashes after editing document)
Younote: (after voice recording function cannot save)
Cube Runner: (sound effects corrupted)
1 report
Blue Skies: report from Developer (cut scene speech is distorted)
Developer aware, update in transit
EirText & EirText Pro: report from Developer (now crashes on firmware 2.1)
Developer aware, updates in transit
Voice Dialer: (does not respond to voice commands)
Whitepages: (?Unable to install??? But works if already installed)
Lexitron: (corrupted sound effects)
Tuner Internet Radio: (AAC+ stream support is now broken)
Tube Status: (random crashes/exit to home screen)
Conflicting Reports
eWallet: (lack of automatic keyboard appearance at login screen, works for some)
Truphone: (out of memory error/ memory leakage from other app? works for some)
What's On: (fails to discover TV stations upon entering zip code/ works for some)
Whoshere: (crashes repeatedly on loading, reinstall does not help, developer is unable to replicate issue)
Note:
One commenter on toucharcade forums RPGGuy claims the 2.1 firmware no longer plays 8 bit sounds correctly which may explain the many sound glitches in some apps.
Note #2: It appears as though applications which prompt for a password upon launching unreliably present the keyboard for password entry. Both SplashID and eWallet appear to have the same issue. However tapping the password blank brings up the keyboard manually.