TP2 poor wifi range !

[nullism]

hi
first sorry for my bad english.
whatever..
i have HTC TP2 PPC and linksys wrt320n router.
when distance from router to tp2 reaches 10 m,connection terminated.
but other phones like Sony Ericsson Elm or Nokia C5 stay connected until the 25-meter distance without any problem.
also every three phones were tested in the same condition(thick walls & ...)
and i have tested a lot of rom.
orginal 6.5 from htc site,energy and so on...but the problem is not resolved.
someone else has had this problem ?
any fix or solution ?

current rom info (energy standard):
os version : 5.2.28244
manila : 2.5
rom version : 01.feb.2011 wwe
rom date : 06/29/10
radio version : 4.49.25.91
incoming call : oops !