Martin,
I have found two KnowledgeBase entries that may help you to solve your problem.
The first one discusses about using LabVIEW (LV) for Sun, and what to check when you receive error 37 when using the serial I/O.
http://ae.natinst.com/operations/ae/public.nsf/fca7838c4500dc10862567a100753500/3c1fa0e91e6356468625625a000d21af?OpenDocument
The next one talks about the location of the serpdrv when receiving error 37.
http://ae.natinst.com/operations/ae/public.nsf/fca7838c4500dc10862567a100753500/ff3549c9a30dc37b862569650049e098?OpenDocument
Hope this informatin is useful.
John M.