Ankur !
We r in the same boat.
I have preciesly same enviornment as u have, LG-LSP-340E, WinXP and same problem of dormancy.
In my case, sometimes it happens very often at every 10/15 min and sometimes it stays connected for hours. I really don't understand what's causing it.
Trying out different options, but no sucess yet.
Pls. let me know, if u find any solution. if I found, I will post here.
Cheers !
Jigs