DAT USB 160 + DPE - every day i get "Error 1400: Alert - Wrong media"

[yurez]

i have dat 160 usb tape drive and DPE 4.0+sp1, running on windows server 2003.

there is one backup job with rotation schedule

on first time cartrige usage (first rotation of cartrige set) i have no errors

but when the second rotations began, every morning (backup is running at night) i see error - "Error 1400: Alert - Wrong media...The media encountered is not correct. "

if a insert this cartrige again and clean it (by clean job of DPE) and run backup job again whithout any changes, a see no errors

backup task properties:
write mode: overwrite all media
autoformat: blank media only

have anyone any idea, why this error appears?
thank you

[skt_skt]

May be you have to rewind the tape before the next write; did u ?