There is an option to update the game on the options/settings/whatever-it's-called menu in the game, too.
And I haven't seen much complaint about graphics or stability issues. That may be a problem with your computer not being good enough for the settings you are running.
You might want to DL the patches from the Flammifer's link, though, since you can keep them on your HDD that way. That comes in handy when you're playing at a LAN and someone isn't patched. Much faster to move a file over a LAN than to DL from the inet. Even with DSL, one of my friends tranferred and installed the 1.03, while another was still DLing it from the inet. and 1.03 wasn't very big.