I put alle the files where they belong, and this is the result:
Client 1 (crashes never): http://www.3dfisch.de/forum/log_does_never_crash.zip
Client 2 (crashes): http://www.3dfisch.de/forum/log_crashed_1.zip
Client 3 (crashes): http://www.3dfisch.de/forum/log_crashed_2.zip
The master did not produce a log file!
Is it possible this is because of the UAC that requires an administrator's approval to write in the standalone's directory?