Error deleting chunk

Hi... We deleted a couple of databases almost a month ago. IN lookin at onmonitor, the chunks still show up. They were physically deleted from the system at the same time. If we try to delete them now, we get the following in the log: Assert Failed: WARNING! pthdrpage:ptalloc:bad bfget Who: Session(3384, informix@hpd270, 28198, -1024355168) Thread(3437, onmonitor, c2ef9b28, 1) Results: Cannot use TBLSpace page for TBLSpace 9437185 Action: Run 'oncheck -pt 9437185' Well, the space doesn't exist anymore, hence the oncheck fails. Any suggestions on how to really delete these entries in sysmaster? Thanks in advance, Joe