Here is some useful information from the MS UAG Blog about IAG SP2 Update 3.
The table in the link is very useful at summerising what is and isn't supported.
Socket forwarding is not supported by any 64 bit Windows operating system, as well as Mac & Linux machines. I have seen this with my Windows 7 64 laptop, which does not work with published RDP sessions, but can confirm that XP compatibility mode does work.
The Network Connector will not work with either 32 or 64 bit Windows 7 machines, as well as Mac & Linux machines. I can confirm this as a customer and I have tested this, although I have yet to test a Windows 7 in XP compatibility mode with the Network Connector, but I suspect it will work.
Although this update was meant to be the "fix" for Windows 7 and IAG, I'm afraid there are still limitations.
IAG is dead.... long live UAG!