unresolved external symbol derfc_ derf_ error

I am using PGI6-1-5 x64 workstation to compile a fortran program
under windows server 2003
I got the following error information
error LNK2001: unresolved external symbol derf_
error LNK2001: unresolved external symbol derfc_

Does anyone have any suggestion and solution ?
Thank you so much

Another thing is if I use PGI6.0.2 win32 workstation to compile this program, everything is ok.

But I want 64 bit version.

Hi defoe2000,

The 3F ERF error functions, erf, erfc, derf, and derfc, are currently not supported in the 6.1 Win64 release. They are being added and should be available with the PGI 6.2 release.