Powerbook G4 Linksys Wireless Network


I am using a Powerbook G4 OS X 10.2.8 (667 MHz, 512 MB) on a wireless Linksys network (WRT54GX). I can receive mail but cannot send email with attachments or emails longer than a couple of paragraphs. I also cannot get my Yahoo mail - I can log in but can't access the In Box. I am unable to do software updates under system preferences - the error is "failed. error occured while checking."

When I connect my Powerbook directly to the DSL modem I have none of these problems.

I am a low tech person that tried calling Linksys but they said it was an Apple issue since my husband's wireless pc laptap works fine on the same network. I called Earthlink and they said it was an Apple issue. Haven't tried calling Apple yet because my Applecare has expired.

I appreciate any and all help!

Thank you very much, Susan