"VersionInfo" property works differently under x86 and x64

Mighty all!

I'm stuck trying to figure out why does

"(Get-ChildItem -Path $env:windir\system32\macromed\Flash\*.exe | % {(($_.VersionInfo).FileVersion).replace(",",".")}|measure -Maximum).maximum"

works ok on an x86 system whereas

"(Get-ChildItem -Path $env:windir\SysWOW64\macromed\Flash\*.exe | % {(($_.VersionInfo).FileVersion).replace(",",".")}|measure -Maximum).maximum"

fails on an x64 system with "input object is not numeric"??

Any help would be greatly appreciated!!