Could you please forward us your system log files for analysis? You can find the same under
XP/2003: C:\Documents and Settings\All Users\Application Data\Paessler\PRTG Network Monitor\Logs (System)
Vista/2008: C:\ProgramData\Paessler\PRTG Network Monitor\Logs (System)
Please send the Logs(System) folder as a zip file if possible.
If you have changed the location of the data folder in the past or if you can not find current log files in the above location, please check your data path in the PRTG Server Administrator Tool on the PRTG server.
Please send them to [email protected]
make some reference to this KB article.