thanks for your feedback. tg3 is again included in 2.6.12 due to relicensing of the firmware. please try that linux image.
As I have already written in http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=314954;msg=27 , this bug still occurs, but only very seldomly.I think it occured only about 3 times since I installed linux-image-2.6.12-1-686, and that was probably about three weeks ago (and as you can see, I first believed I would have gone)
Willi