internet explorer/hibernation

I´m running xr pro and using internet explorer version 8.Recently my
hibernation and standby functions stopped working, and also when I tried to
delete my history or change any settings in internet explorer it just hung.
I removed explorer 8 and that autamatically left me with explorer 6 but I
still had the same problems.I then re-installed explorer 8 and everthing
worked fine including my hibernation and standby functions, and now after a
few days the same problems have started again: I went through all the steps
above but this time it did not work. I´ve tried restoring the system to the
point when everthing was working but that also failed I`ve tried kellys
corner, microsoft help sites, and now I´m stuck. Do any of you
knowledgeable people have any suggestions on how to fix this problem thanks.