iTunes not enough memory available

I have posted the same message a few months back regarding iTunes being out of memory.
I remedied the problem by reinstalling an older version of iTunes. The other day - without thinking - I updated iTunes. Ever since everytime I try to open iTunes I get the error that there is not enough memory available.

I have an iMac G5. Last time someone suggested that I upgrade my RAM. I just installed an extra 512 meg to make it 1 gig. Same problem.

I bought my daughter an iMac G5 at the same time I bought mine. She only has 512 meg of RAM and has never had a problem.

Any thoughts greatly appreciated. Thank you.

maybe take a look at activity monitor. is there anything hogging lots of ram? how much does it say you have free? you have 1 gig in a new computer so thats really weird.