Applies to:Oracle Server - Enterprise Edition - Version: 10.2.0.1 to 10.2.0.3
Oracle Server - Standard Edition - Version: 10.2.0.1 to 10.2.0.3
This problem can occur on any platform.
ORA-600 [kgscLogOff-notempty], 
or ORA-600 [kgscLogOff-notempty], 
with a Call Stack like:
... kgscLogOff kkslof opifcs ksuxds ksudel ...
Abstract: OERI[kgsclogoff-notempty] can occur during logoff
This error occurs during the logoff operation, hence the impact should be negligible.
This is fixed in 10.2.0.4 and above releases.
One-off patches may be available depending on your current release and operating system.
To obtain a patch from MetaLink:
1) Click on Patches.
2) Click on Simple Search
3) Enter patch number: 4887675
4) Select your O/S
5) Click Go.
As workaround, avoid Killing/Terminating the Session Abnormally.