Not sure what the actual problem might be that you are currently experiencing but I thought I would test, since I do love my Hyper-V.
So off I went to technet. Downloaded the ISO and installed into a new VM.
Then back to the internet to download SP2 for Windows XP Pro 64bit and installed as the Hyper-V integration service would not install with out SP2
Then installed the integration services and it just worked. No issues. And no work-arounds needed.
