Yeah, that appeared to be the problem. Some modules would work okay, whilst those that were built with v1 of CEP needed the hak and tlk files from CEPv1 too.
I also needed to download the latest patch for CEPv1, which was basically a hak file.
All modules have now bee ntested and work as normal using CEPv2 and the additional CEPv1 files.
Thanks to all who helped.
