Citrix mapped drives and crystals reports

Has anybody come across an issue with Citrix mapped drives and crystals merged files.

I have updated the crystal DLL's my application uses to 11.5 and created a new setup kit to distribute my app including these new DLL’s along with a merged file call crstalreports11_5_net_2005.msm the Visual Studio setup app added. The installation runs fine on the Citrix server and application runs as well. When I come to run any report on the Citrix server I get an error “procedure call or argument is not valid”. If I remove the mapping to the drives the reports run without any errors.

I need to keep the mapped drives on Citrix so removing the mappings is not really a solution to my problem (which is a shame really)

I am using Visual Studio 2005, Crystal Report XI and Citrix 4.5

Any help would be gratefully received