[popper]

it sounds like your wireless router is one of the cheap and cheerful 11b or 11g ones and so cant keep up the traffic throughput due to CPU overload.

still, 2.5 and 3.5 MegaBits a second, pc to pc seem very low even for the old 11b 11Mbit/s max kit, never mind the 22Mbit real max speed you might see now and again on the 11g kit.

perhaps you should have got some 11n kit for both ends today, as that can supply far more throughput due to better CPUs inside, and most have 1 gigabit/s switchs inside them so are far better at greater PC to PC wired data throughput or current 100Mbit+ average wireless throughput.