CF Error Log

[AlexSyn]

Issue with CF

Every time an attempt is made to execute any function from the Cognos Finance control panel, the error file grows to 4gb.  When launching the application and it is locking up the system and the error log files begins to grow rapidly until the server is rebooted. Once the server is rebooted, the error file will stop growing (error file will reach over 1 GB in less than 15 minutes)

Have tried the following with no success:
1)   Check permissions on the SYSOUT directory and the Errorlog.SF file
2)   Rename the Errorlog.SF to old  and let it create itself again
3)   Replace the xxxsec.SF file with one from your backup

Before this happened there was an "unable to create system error log" but no longer getting that error, but instead getting above error. 
Any advice?