I had something like this happen before on a 4.1.3 box, I upgraded to a new service pack to fix another bug and it fixed that for awhile until they patched that patch with a version "b" and it broke it again... go figure =)
I have also opened several tickets with TAC and no one can give me an answer or assist in fixing it... Kinda followed the link in the above link to the bug report and they still haven't posted a fix... oh well, reset's usually occur at night and if they do happen during the day the end users barely notice if they notice at all...
------------------------------------
Dallas, Texas
Telecommunications Tech
CCVP, CCNA, Net+
CCNP in the works