Congratulations,
what you have found is where the CATalog files are stored before being merged into the database. I assume that the database is either not getting written to, OR the database is working fine now, but earlier it wasn't. you can either run the utility mergecat.exe (found in the arcserve directory) to put the cat files into the database (note: 1.5 GB will take ages!!!) or you could simply delete the files and check the activity log for any errors concerning the database.
Nobby////