Python 06408-XXX Backup Exec 8.6 Errors and cleaning

I've got a PE2500 with a PV-100T DDS4 drive (shown as Archive Python 06408-XXX in device manager) which constantly errors. It requires cleaning during almost every job. I'm using the latest Veritas driver suite (20021101) and firmware 9050 in the drive. Backup exec 8.6 release 3808 is in use. I use Sony DDS3 tapes in this drive.

Is the drive compatible with DDS3 tapes for writing?

In 280 hours of use, I've amassed  1001 soft read errors, 14 hard read, 638000 soft write and 14 hard write errors.

The drive is cleaned regularly, almost daily.

Any ideas?