2D Panels and Framerates

Hi,I'm running FSX in 1600x1200 on each of two identical Iiyama 19" monitors. When I have just virtual cockpit on the left hand monitor the framerate on average is stable at about 30 fps. However, if I add 2D instrument panels such as PFD, MFD, throttle quadrant this kills the fps and reduces to average 20 fps. I don't understand why - surely simple 2D graphics shouldn't do this? I've tried lowering the resolution on the second monitor but it does not help. Even just adding the PFD reduces the framerate by about 6 fps.My current system specs:MSI K8N SLiAMD FX-60 Dual Core CPU2G Corsair PC3200 in Dual Channel Mode & Command Rate 1TXFX Geforce 8800 GTS 640 Mb XXX EditionCreative Audigy 2Any got any ideas please? Do you think anything in SP1 will help?Many thanks!