hardware or software (signal on 2g with newer firmware)

right now my signal sucks BAD, one bar MAYBE most of the time no signal. funny thing is, my GF has a 2g iphone too and gets better signal ALL the time. i used to have good signal when i had 2.0.2, but then i updated to 2.1 with quickpwn i might have had good signal for a while. i got sick of the crappy signal on 2.1 and thought 2.2 would solve the issue. it didn't help (makes sense huh, 2.2 and 2.1 baseband are the same). my question is, is it the baseband and are lots of people experiencing this? i get one or two bars where i USED to get 4-5, GFs 2g iphone has good signal too, she's on 2.1 unlocked with t-mobile. i'll list all relevant details:

GFs 2g iPhone:
firmware 2.1
baseband 04.05.04_G
8 gb
t-mobile carrier

my 2g iPhone:
2.1/2.2
baseband 04.05.04_G
8 gb
t-mobile carrier


my guess is my phone is almost a brick. i owned a refurb 8gb, then got it replaced for another 8gb (probably a refurb and my current phone). if this is a software fix, i'd like to get it working, otherwise, i'll go through the pain of going to the "retard bar". speaking of which, in order to virginize i just put the phone into DFU and do a simple restore to 2.2 right?

thought i'd mention, i tried the scotch tape on the back of the sim card to make sure the sim was seated properly. that = no good. i'm guessing my antenna, or transponder or something is bad. wifi signal is great, phone operates perfectly otherwise, just signal isn't as great as other iphones.

i've heard from people that it is the commboard, but the wifi works perfect. i think its the baseband, but not sure. any ideas? i'm sick of really dynamic signal which ranges from 2 bars to no service.

also, i'd like to say that i can make phone calls and send/receive text messages when i have 1-2 bars. i can use edge when i have 3-5 bars. however, overall, signal has been choppy and very dynamic.