Parallels mobile unusably slow on direct connection

Hi, I have Parallels Desktop 7 for Mac running and it all works well.

I use the Parallels Mobile app on both my iPhone and iPad and both of these work great over both 3g and other people's wifi.

When I try and use the app on my own wifi however the system notes it as a direct connection but it is totally unusably slow - appears to be about 90 seconds per screen refresh. Using Mocha VNC on both my devices when connected to the local wifi works perfectly fine.

It doesnt seem logical that direct connection over the same wifi network is slower than a 3g connection especially when other VNC apps are working fine on the same network