gnome fails to load on login after bootup - unless bootup first in win xp
I am running fedora core 4 with kernel version 2.6.11-1.1369 on a new laptop (64 bit architecture, pentium 4 processor - let me know if additional specs are useful). The system had been working very well for a few weeks. However, in the last two days I encountered trouble logging in after booting up - gnome (ver 2.10.0) startup seems to hang (I have mouse control, but none of the loading icons show up no matter how long I wait). This happens for all users, including those using default start-up scripts. I am able to access the failsafe terminal and can load any programs I want from there. I don't have kde or any other desktops installed to test. I have, however, been able to login to gnome without trouble if I boot up first in win-xp and then reboot to linux. I have also noticed that on shutdown I get an "NFS locking failed" error. I had been getting this error intermittently before but without any troubles on the following login. I have been wary of disabling NFS since I don't know how to reenable it if it's needed for my partition that's shared with win-xp. The only changes that I made to the system immediately before encountering this problem was installing firefox 1.5 and changing the sound driver used in xmms and mplayer - both changes seemed to work.
I am very new at running my own linux system - so any help would be greatly appreciated. Thanks in advance!