Instead of Importing your slides, try copying and pasting them from the original Project file into a new instance of Adobe Captivate and see if that makes any difference.
Let us know how you get on.
Adding to the correct answer of Mark: this is an unpatched version of CP4 (build 1596), please ask your colleague to install the update released in May 2009. He can use the Updates option in the Help menu of CP.
Upgrade didnt work unfort., but the copy paste is good enough work around for now. Hopefully upgrade to cp5 soon anyways.