Problem connecting my ps3 to my iMacs Internet sharing

[PravusIgnavio]

I recently set up Internet sharing through my iMac, no wifi router, which runs snow leopard. I was able to connect to this wifi network using my iPod touch with no problems whatsoever, it acted like any normal wifi network. However when I tried to do the same thing with my ps3 it wouldn't work. Using the easy method it proceded fine until it got to the connection test where it said that It could not find the ip adress. So I tried the custom method. The ip and everything passed however the connection test failed. I forget what the error message said but the number was something like 807 something something and that the ip was valid for Internet or something I typed this question using my iPod touch so I know the Internet is working. What am I doing wrong? I don't know a lot of tech stuff so explain it to me as if I was a 10 year old.