Make sure you've set the execution policy in the 32-bit version of PowerShell or that you're invoking the 64-bit version of PowerShell from Visual Build (i.e., %WINDIR%\Sysnative\WindowsPowerShell\v1.0\powershe ll.exe in the Override field on the Options tab).
http://www.kinook.com/VisBuildPro/Manual/6432bit.htm
http://www.kinook.com/VisBuildPro/Ma...hellopttab.htm