7.5 Sign-In hangs forever.

Okay, every instance of MSN has run perfect - so does 7.5 -- here's the
thing:

When I sign - in, MSN connects, the 'icons' stop spinning, sometimes my
other contacts can see me logging in, however, before my contact list etc
appears, my computer accesses the hard drive as if it's loading 4 instances
of Photoshop all at once. It thinks and thinks and thinks -- sometimes
long enough for MSN to say: 'sorry the connection was lost'. -- USually it
will "connect through" on the second try. Once it's loaded, everything's
fine. My question is: why does it do this?

Celeron 1.8 128 DDR
Win XP Home.