display error??

i'm new to linux and i really want to try it out and this is my first attempt to install any linux of any kind.i went with ubuntu because it seems to be popular amongst the linux community.anyway, while i'm trying to install i get this message and i don't understand the problemhttp://i140.photobucket.com/albums/r1/Dragonmantek/Picture1.pngas you can see i'm running off of parrallels 3.0i have an imac. Model Name:    iMac  Model Identifier:    iMac5,1  Processor Name:    Intel Core 2 Duo  Processor Speed:    2.16 GHz  Number Of Processors:    1  Total Number Of Cores:    2  L2 Cache (per processor):    4 MB  Memory:    1 GB  Bus Speed:    667 MHzand i guess since its a display problem, graphics are important?  Chipset Model:    ATY,RadeonX1600  Type:    Display  Bus:    PCIe  VRAM (Total):    128 MBany solution?