I'm not sure. I'm guessing there's some Windows configuration setting different on that particular machine?
This articles indicates that with 2003 SP1 and later, the 64-bit view will be always accessed, unless the KEY_WOW64_32KEY flag is used (not possible from 32-bit Visual Build):
http://msdn.microsoft.com/en-us/libr...=vs.85%29.aspx
Although it's not entirely clear if the Windows 2003 behavior is for 2003 and later or just Win2003. So it could mean that for a Win 2008 remote machine, the first statement applies (If the client is a 32-bit application, it accesses the 32-bit registry view. If the client is a 64-bit application, it accesses the 64-bit registry view).
One thing you might try would be updating the client to 2003 SP1, since the behavior changed with that version (but this wouldn't explain why it works on all remote 2008 boxes except one).
Another option might be to use 64-bit Windows + 64-bit Visual Build on the client.