i have a linksys wrt54g router and wmpg54 wireless card. when i first set them up(two desktop pcs in separate rooms about 20 ft. apart) all was fine. my signal strength was always good or very good. lately its been very low all the time. i lose my internet connection at times(broadband cable) and get very slow downloads and sometime freezes. nothing has changed since original setup. any suggestions on signal increase? i've only had it set up for 1 week.