i cant get p2p apps to work

i need to make a long post but i will keep this short and ask if i can write a paragraph or 2...i had a d-link for 2 lan machines and it worked fine for almost 2 yrs, i went to hospital for 6 weeks and when i returned it wasnt workin...i tried to get it goin and it wouldnt so i threw away lan #2 machine and bought a new computer - keeping the router plugged in so it kept the setup nfo. it still wouldnt work, so i went and bought a linksys router on sunday and it wont work either...the setup nfo is confusing and i need somebody to critique my setup...i have read many faqs and the linksys propaganda and it is only confusing ( in one example linksys sayd only use dhcp and in another it says never use dhcp)i can access the net with all other apps except mirc and dc++. i have a cable connection and 2 new dell computers. i tried the dmz routine but the ip kept changing - i set it for lan #2 which has the p2p files on it, the next day i go look and the dmz is still enabled but it is now for lan #1...wtf??? this sux so plz help...no ports triggered, 3 ports forwarded 1 mirc, 1 ident server, and 1 dc++, upnp is disabled. now, you know everything about me except my social security @ and you aint gettin it. tkz for any help,aloha