I was having the problem not getting out, so heres what I did:
I had to flash my psp, and also I ran key cleaner on it (fixed my corrupt 5 from Lumines downgrade but that shouldn't have made a difference)
After my flash, and re-settig up my network with my WEP key, it began to connect out, but still wouldn't log in.
I checked the SIP provider and it turned out that I had been entering the username I created when I started my account, for sip service however they said to set device configuration to the SIP phone # ie:
username:fourmyfriends is wrong
username:06937848XX would be right (I don't know about the number I made it up dont try to call it)
After that I was finaly able to connect.
Now my only problem is tracking down where the very bad 'click' or 'pop' is coming from. It's verry patterened, almost like its noist of packet transffer. It pops like interference.
I think my problem may be in the encrypt/decrypt of the WEP causing a lag for translation that comes out as a pop. I'm going to try turning off my WEP and see if it helps. If not then I'll be wondering if it may be the ram shortage on the phat

any help or suggestions about the pop in the line would be appreciated