Whoever sold you the wrt 54 needs a kick up his butt. They have firmware problems. Linksys are a very, very good brand but the 54 series & particularly the wrtg54 are "lemons". So if he told you it would be adequate he deserves to lose his job because he obviously doesn't know about the product properly. wrtg54's are reknown to be unreliable in UPnP mode, & also sometimes unreliable even when port forwarded. Someone who used one & had a fix http://www.gnutellaforums.com/showth...843#post196843 but that's only for people who know what they're doing.

If switching to UPnP, normally best to save settings, not sure about linksys but some you need to reboot the device to save settings properly. My initial gut reaction to your post was it is the linksys device being unreliable which is your problem. I might be wrong. But with the no. of wrtg54 or just linksys 54 router postings here with problems ... all same or similar symptoms ...