Hi all thanks for your replys,
Yes the dongle is straight into the Mac as I dont have a spare PCI slot (two LFG cards)
Richard thanks for the tip about file sharing, it is on at the moment I will try turning that off, although it is turned on on the back up server and that is working fine.
I ment to mention in the orginal thread that catalyst sometimes loses the USB keyspan serial adaptor in the custom serial output box when it doesnt see the dongle. The TCP ones are fine -this is what makes me think it is a hardware fault.
Is there diagnostic tool for the USB bus?