Odd. Just my experience/install but has been rock steady for 2 years now.
Make sure something else isn't trying to autoupdate on you, or antivirus turned off, etc.
Good luck!
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4x2.66 GHz Xeons, XFX 4870 1 GB, 11 GB DDR2 RAM, Win7 Pro x64, 120 GB OCZ Vertex2 (MLC, Sandforce)
26" VIZIO 1920x1200, Logitech FF 3D Pro, CH pedals, Track IR4