If it works for other groups there must be something different for this one. If you can't track down what it is, then try recreating the group and see if it works. If it does, just delete / rename the old one.
It could also be that users in the group are following a different procedure to the other groups.
Failing that you will have to reconcile CL_CALL_LOGGING and SA_EVENT for your report.
Just out of interest why are you still using version 8? Version 9 is so much better in both performance and features.