Memory problem on win xp pro x64

I am trying to resolve the following problem: The program (3-0-2) running on windows is not able to use more than approximately 1.5GB of memory. After that Singular stops and crashes. Is there a way to configure the memory usage / program so that this does not happen? I am using Windows XP Professional x64 operating system and 4GB of memory and have the /3GB switch set in boot.ini.

The message I get from Singular is:

error: no more memory
System 1187904k:1187904k Appl 1173232k/14174k Malloc 1615k/0k Valloc
1185792k/14174k Pages 148224/0 Regions 1158:1158

halt 14

Does anyone have a solution to this? Best regards.

The provided binary for Windows is a 32bit program based
on the cygwin environment.
Singular uses the malloc system call (provided by the cygwin runtime)
to access memory.
How much memory is available depend only cygwin and the operating system.