ontape and norewind devices

We like to upgrade from Online V5 to V7.21. During our tests we saw that Online V7.21 can store to norewind devices (ontape -s) but is not able to restore from this device (ontape -r). When restoring, ontape reads the header pages first, then prompts for a 'Y', rewinds the tape and quitts with an error, because the first data on tape is an application-header and not the saved database. Calling Informix-hotline, they said, this is a feature, not a bug. ontape does only support rewind devices in V7. Any ideas? Peter Schneider, speaking for my own.