Zip Plus doesn't work with Adaptec SCSI card

[amiga1260]

I have an Adaptec 2904 CD SCSI card. The ZIP drive works only when no other SCSI devices fitted. Now I fitted a SCSI harddisk in my PC, but the Zip Plus doesn't work together.

The Zip drive is fitted with the original cable with a gender changer.

This setup works with a Squirrel SCSI controller and with the Blizzard SCSI kit. :-)

[amiga1260]

When I attach an external SCSI CD-ROM, this problem won't happen.

I think I buy another SCSI controller like the DAW 2974 controller and has auto boot function.