Sorry, Adrian, I totally misread your original message.
Have you run through this KB, which guides you through troubleshooting failures in the PM Import?
How do I troubleshoot the Patch Management 7.0 - PMImport failing to download successfully?
https://kb.altiris.com/display/1/kb/article.asp?aid=48344
If you end up where you started (the final step, assuming the first few steps don't help, is to run a manual download), please post any errors regarding PMImport.