Hi,
could you try going to your environmental variables, then deleting the RNNAME variable. Then initialise your database (note that this will blow away your current database information and replace it with a fresh empty one). When you then need to restore from tapes made prior to the initialise, you will have to merge the tape into the database. This will then allow you to restore.
If this doesn't work, then make sure all your jobs are saved as .asx files. Then rename the 00000001.qsd folder in the arcserve directory. restart all the engines and then try a quicky job. Then check for the error, if the error is gone and you can write to the database, then load up your old jobs and see if they write to the database. If they don't then the problem is that one of the jobs is corrupting the database. Also, you will need to resubmit the database pruning job after you have renamed the 000001.qsd folder.
A possible cause of corruption is simply stopping the job in mid flight whilst it is in process of updating the database. In fact there are quite a few possible causes of database corruption.
Oh well, hope this helps....
g
