Hi Ludek.... I checked that both ExportModeller.dll and Tslv.dll are properly registered, but still got the message. The only export format that creates this error is the PDF export; all the other formats work just fine; and yes, we are doing the exporting via API calls (but it still occurs if I do it thru the viewer). And unless Arial has become an unregistered font, well..... ;-)
I will check the C++ runtime options, make sure they are current. Then I will try out your suggestion on running a special test report. One caveat, though; I'm on vacation next week, so I may not be getting back to you until the beginning of December.