TF2 Crashing??

[DrDoomNGloom]

I have been playing for a couple of weeks without any problems, but today after about five minutes the game hangs forcing a reboot. Weapons upgrades are not dsiplaying, just stock weapons ...................is this the norm?? I thought I had found an alternative to Mafia Wars only more graphical and without all the spam drama, but if it will not stay running then......