Is this a Tileproxy Issue?

Hello,Can someone please help me? I have a very powerful PC with a fiber optic connection (currently capped at 20MBs). This is what usually happens...I start a flight with TP everything is fine frame rates are on average 70fps with all sliders maxed , REX running, PMDG 747 on the runway ready to go.I take off and 10-15 minutes into a flight the clouds start appearing like squares with the MS flight simulator X logo on them. I then start to loose my textures (see attached image)sometimes they revert back and everything is OK for a while then usually REX updates and it freezes, end of game. The last image shows FSX working fine. I have tried both DirectX10 and 9I have the latest updates for all my Windows7 64bit applications and a NVIDIA GeForce GTX 480 with the latest drivers installed: GeForce/ION Driver v266.58Version: 266.58 WHQL Release Date: 18.1.2011 (beta I believe. I also use Nvidia inspector but not sure why or what it does (see screen shot for settings.Any help please?One last word it seems to be only when I run TP.ThanksPaul