Is what you're talking about related to the yaffs2 bad block error messages in
this post of yours that you asked me to look into?
I have an idea relating to the above, but, its rather theoretical at the moment--meaning it can certainly occur in theory, but, I've not seen it "in the flesh" so far. I'll have to do a few tests to confirm my ideas first.
Get me a logcat and dmesg output using adb the next time this happens--both in your ROM
and in TnT after you boot into it following the first nvflash as you say. For TnT you'll have to flash the zip file in the attachment immediately after doing the nvflash to enable ADB (and root) to grab all the logs.
EDIT: I looked at the updater-script for the TeamDRH-ICS-Beta-1.1 ROM as part of troubleshooting another problem I was having a few days ago, and I noticed that you were formatting the cache partition as part of the install. This isn't a good idea: Since /cache is always kept mounted by CWM recovery, formatting it
while it is mounted will trash the filesystem for sure. If you want to wipe things clean, let the user do it via CWM--the install procedure already does this. The same logic applies to the other cleanups the script is doing.
Unlike some other ROMs (notably the HC ones and the latest Stock 5699), TeamDRH-ICS does seem to use the /cache partition actively, and using a corrupted filesystem might be one of the reasons for the problems that some people seem to be having. It's worth looking into.