console problems, quick question, please help

Ok, I've asked around alot and haven't gotten any decent answers.

My xbox360 will often screw up a bit, and it sounds like the fan turns off, and theres a few crackling sounds. Some times it will freeze or disk read error (especially with the new tales game), other times it will slow down/ freeze for a sec or two, and then work.

Is there anything I can do? also, is it better to have it horizontal or vertical for problems like this?

Thanks for any help :)

P.S. the xbox is around 2 years and a bit old.

cool, thanks for the answers, that helps alot. I hope it rrods soon before my warranty expires!