Connectivity problems since patch(EQ)Follow

First, Let me say thank god that I finally found this site and may now be able to get some much needed help:-)

System info:
Comp1:
HP pavilion a320n
2g P4 processor
512mb ram
256mb video card
on board sound card
80g HD

Comp2:
Dell
2.4g p4 processor
512 mb ram
integrated video and sound card
(this comp standard purchase added 256 mb ram)
40 gig HD

As you can see I am not computer knowledgeable so can only offer you the above info as far as set up goes. Comp 1 is host on cable modem connected to Linksys Router 2.4Ghz. Comp 2 is on wireless card.
Problem:
1.Upon entering game,regardless of zone, one or both comps will start to get what I'd call packet loss and start to get real laggy and even go link dead/losing connection. Thought it might be our router and have loaded new firmware. Have tried our cable company who says we have not had any cable problems.
2. Comp1 will go to black screen upon trying to login,screen minimizes and then has to close with eq error appearing.
3. Have noticed several times where if I am on comp2 playing and BF is on comp1 playing(in same room), and we are in same zone, he disappears for about ten seconds and then reappears. BTW, he died in game last night on that one.

We are at our wits end with this problem and I know my information has been sketchy but I am hoping someone can help me before we get so aggravated that we just quit using comps altogether. I also know that comp2 is not the best setup but it worked fine until this latest patch. So please give me some tech advice minus the must replace motherboard as this dell was purchased 4 months ago.:-(