So, what I'm trying to accomplish is that my exceptions get logged into the rolling log file (which I use for other things, especially tracing - which is VERY important in the environment I'm working in - too).
Problem is that I get all traces into rolling.log, but the exceptions get logged into files with the following name scheme:
{guid}rolling.log
Smells like a bug...
Edit:
Found the solution. The log - file is locked, EntLib creates a new one with that "Guided" (pun not intended, it just happened) name. Case closed. :-)