System crash during backup

We are running 7.14 Informix on a 10.10 HP box. This is a single processor machine. Recently we had the system crash during a normal backup. We thought the tape may have been bad the first time but it crashed a second time with a different tape so I hesitate to say that we had two bad tapes in a row The error stated Function write to tape failed: code -1 errno 5 I know the errno five is an I/O failure but I don't know what the code minus one means. So it may have had trouble writing a tape but why a system crash! The caveat to this is that the vendor does not allow ontape -s backup but instead forces you to use a small application program to perform the basic functions such as status and backup. Now to top it off the vendor says we should use tapes only two to three times because Informix has a known bug that on a single proc system a bad tape can cause a system crash. Is this true? I would have thought that I would have seen this complaint in this newsgroup if this was truly the case. I'm more inclined to believe it's a problem with the scripts we have to use rather than with Informix. Has any one else any experience with bad tapes causing system crashes/ Thanks in advance for your response. Hammer