Hang on writing index solution

[swalker]

Context:

Retrospect 6.1.230 on MacPro OSX10.5.6 with Atto SCSI UL5D and LTO-2 tape drive

 

Symptom:

Reads&Writes OK, but hangs exactly every 500.0 MB on "Writing index"

 

Tried unsuccessfully:

Reinstall of OS and applications, new simple Retrospect settings, swap of cables and SCSI channels.

 

Solution:

Use new tape. So all this work and the problem is a defective backup tape > how does it manage to read&write data, but cause a hang writing an index? Troubleshooting backups has always been a pain. Glad they work most of the time. Anyway of making things less obscure?