Backup Solution for NetWare-Suggestions?

I’ve got a single-server NetWare 5.0 LAN, currently running ARCserveIT 6.6. Every time I add a service pack or a new feature, I get a variety of problems with ARCserve, including failed backups, invalid headers signatures, and all-out freeze-ups.Anyone out there got any suggestions for a solid backup solution? We use a single 40GB DLT drive. Recommendations and war stories are welcome.