Did you uninstall the previous version with the Config Panel or by using the specific uninstall tool ?
Please use this tool : »ftp
and wait for it to finish the uninstallation of previous versions that might have been in error/unremoved; note that the tool will reboot your computer when done in 95% of the times (when removing startup apps from the suite if they're still there)
And then reinstall the security suite.
Keep us informed how that went