Order will not bounce back to my site: 'script error'

[DavidPrintkit]

After a week of constant problems on our site we've managed to iron out the bulk and there is now one which I can’t seem to beat.

Our site runs on multiple domains (printkit.co.uk; kyocerashop.co.uk; kyoshop.co.uk etc) which all redirect from printerkit.co.uk.

We've just changed to 'use relative CGI-BIN URL's in catalog pages' so that the shopping cart shows the correct status whatever url you are browsing on (before it would bounce to printerkit.co.uk to add to cart and then bounce back to browsing url e.g. kyocerashop.co.uk and the cookies would not register and so the cart would show as empty)

The site runs fine and the cart works well but after it bounces to Protx and you’ve entered your details it fails to bounce back to the site. This means that the customer does not see the receipt, it looks as if the purchase has failed, and we don’t get confirmation.

This is the error it shows:

A General Script Error Occurred

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Error: Your shopping cart has expired, orders must be completed within 3 hours or they will be automatically cancelled.
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Press the Browser back button and try again or contact the site owner

This is the url its trying to reach when it shows the error:

http://printerkit.co.uk/cgi-bin/os000002.pl?SEQUENCE=3&ACTION=Finish&ORDERNUMBER=XXXXXXXXXXXXXXXX&REFPAGE=http%3a%2f%2fwww%2ekyocerashop%2eco%2euk%2f

This purchase was processed from kyocerashop.co.uk and at first glance it appears as if its trying to find the cart on printerkit.co.uk and can’t due to a cookie error???

If I manually edit the url to read

http://www.kyocerashop.co.uk/..........

**addition of www and change domain**
then it works fine and shows the receipt.

Does anyone know what I’m doing wrong?
All help is welcomed as I have no more ideas of what this could be.

Thanks

[DavidPrintkit]

changes

If I manually edit the url to read

http://www.kyocerashop.co.uk/..........

**addition of www and change domain**
then it works fine and shows the receipt.

changed my network settings because for some reason i deleted the www. from the cgi-bin and acatalog urls. This adds the www. where it previously was not.

can i edit these boxes in the network settings just to read '/acatalog' and '/cgi-bin' ???