Peter, what version of SL and what version of Crystal Reports are you running?
You might try one ODBC change to see if it makes any difference. Configure the ODBC definition for your application database using the SQL administrator credentials. On the DSN configuration page, look at the Use ANSI option settings. If they are checked, uncheck them and try the report. If the are not checked, check them and try the report. I know that sounds strange but I have found that the ANSI settings affect various reports built under prior versions of Windows talking to different versions of SQL.
The other common issue with some user developed reports is that they are built with a particular printer type and then the workstation running the report cannot resolve the printer optimization codes in that report. If you open the report in Crystal and go to the printer setup, check the No Printer option. This causes the report to be more generic and lets it work with any printer.
Not sure if either of these will help but they are things I try when I get an error similar to this and one of them usually fixes the issue.