How can the network make FS to stutter ?

I have WideFS on a client running Win XP Home and FS stuff on a separate server running Win 7 Prem Home 64 bit. On the client I have run FS Flying school and experience severe stutters in FS9 because of that. In the WideFS.ini I did add Protocol=UDP as suggested and that did indeed improve performence. But still there are more noticable stutters when FFS is used over the network. Why? The application FFS isn't run on the server computer. I also use ASA with WideFS and gets no performence issues. Also noticed that the fps doesn't drop I just get stutters.That leads to the question would it be better with regard of performence to run FFS on the server itself?My FS server systemAMD X2 6000+4 Gb RAM8800GT 512M DDR3 videocard at 1920*1200*32Win 7 64 bitNy client systemAMD 64 4000+2 Gb RAMATI 9800PRO 128M DDR videoWin XP Home