We have exactly the same Problem. (Windows 2003 System, SDLT-Tape, EXEC 10.1 Rev 5629)
I'am interested to hear if there is a solution until now.
I tested on our Production System (Windows 2003 Sp1 Tape Drivers) and our
Testsystem (Veritas Drivers), no difference.
I tried several knowledge base Issues on this Problem (Automatic Media Remove Alerts), it exists since Version 7... and it was working fine in Version 8.6 with some Registry Entries.
It seems to me that the EXEC programmers just use a random memory location to pick up the Respone timeout ...