Ben,
There are some issues with SP2 that are currently being delt with. The biggest issue with SP2 is that it by default turns on the XP firewall. This can cause for any number of security warning and other network related issues. Here is a link to a KB on how to deal with XP's firewall in LabVIEW
http://digital.ni.com/public.nsf/websearch/91A1EA23DB25BE4386256E54007AE9E8?OpenDocument
Hope this helps! Let me know if you would like more information.
Have a great day,
Allan S.
Applications Engineering
National Instruments