Playing D2 On Mac...help!!!

when i start up d2 on my macbook, i get an options window that allows me to configure my video settings. i am running a 22' secondary display which the game runs in. If i select the option to have d2 run OpenGL, it doesn't work, i get to the menu screen and its all glitchy. I have to select the "software" option, i don't know why becuase macbooks are new and it says the "software" option works best with older video hardware, and i thought my hardware was fairly new (although i know macbook video cards are pretty lousy) i still figured it could do it becuase d2 isn't that demanding of processing power. The real problem though, is the resolution. the biggest they have to choose is 800x600,72hz. But this looks pretty bad on a 22' monitor. is there any way at all that i can get the resolution to something higher, like 1682x1050? there must be some sort of plug-in or some way of doing it. please help!!!

macbook
osx 10.4.9
1.83 GHz intel core duo
512 MB 667 MHz DDR2 SDRAM