Reasons for your problem.
1: You didnt buy New Vegas for the PC.
2: You bought New Vegas for the PS3.
3: You bought a PS3.
Im mostly joking with you!

Dont worry. I own a PS3 too. Though i dont play it much.
Honestly, all these "bugs", "glitches" and "errors" everyone talks about i havent encountered once. I may get the random crash every hour or so, but i quick-save after every gun fight.
I have Lonesome Road, and ive played it flawlessly.. But i suggest you get a computer that can handle most games, and start buying your game for it. I own all 3 consoles, but im a computer gamer for a reason. Everything is just slightly better.