For what it's worth, I'm getting the same issues today on a Windows2008 box, Sybase 15.7 client install and Strawberry 5.18. Looks to me like the 64 bit versions of the libs are not installed OR that they aren't recognized as such by the build. I had the same looking issues building MQSeries on the same box until I "convinced" the Makefile.PL for that module to go use the Lib64 directory to find the right libs.
in reply to Re: Installing DBD::Sybase using CPAN
in thread Installing DBD::Sybase using CPAN