Be careful about using 'omnidbutil -clear', if you have any currently running session, it will kill them also
Maybe a different approach is needed here. At the command prompt on the cell manager
Windows
cd \Program Files\Omniback\bin
omnistat
If you see any sessions, start with the oldest session ID, and run
omniabort -session [session_id]
which may or may not abort a session. For those that won't abort, start your Task Manager, get a list of running processes, and look for any of these
bsm
rsm
csm
asm
msm
If you see any, kill the process. Once they are all gone, stop DP restart it and now, run
omnidbutil -clear