It's Stuart here from the BackupAssist team, thanks for posting on our forum.
I have seen a little bit of this lately and our development team is looking into this.
Have you tried to update the driver through device manager at all? Since BackupAssist uses the Windows API's, it's most compatibility is with native Windows drivers.
If you've got another machine available (even if it's running a workstation OS such as XP or Vista) you could try the 30 day trial of BackupAssist to see if the same thing happens on another machine (which would point it towards being the tape drive itself).
However; would it also be possible for you to send in a set of diagnostic information so that we can look into this for you further?
To send us diagnostic information please follow these steps:
1) Go to Contact Support (from the bottom-left corner of the console) -> Contact Support
2) Fill out the form and ensure that the Submit system diagnostics checkbox at the bottom is checked.
If you have anything else to add, please reply to my post or send an e-mail directly to firstname.lastname@example.org