Network file transfer slow while PC is turned off

[woomera]

my network setup is:
-TP-Link wirelesAP/Router with DD-Wrt installed
-Computer A - File server win xp sp3
-Computer B - My laptop win 7 x64 sp1
-Computer C - Wife's pc win 7 x64 sp1

issue: file transfer from/to xp from my laptop very slow while PC is turned off. as soon as i turn pc on all gets good. this looks really weird to me, anyone have any idea what can be the cause?
all of these 3 are connected with cable not wireless, i also have tried changing the port of the laptop cable on the router but didnt change anything.

 

[Ztruker]

Sorry but I don't understand? Do you mean when your wife's PC is turned off the xfer is slow to/from your PC?

Did you install DD-WRT to bridge two routers?

 

[Lantz]

From what I'm getting he means this: When his wife's PC is off, the transfer speed from his Laptop to the XP system slows down.

Not quite sure how the PC turning off would result in a network slow down. Do you have any QoS or other speed limits set in DD-WRT?

 

[Lantz]

Just a sort of off-topic question. Why do you have a wireless access point if none of these connections use wireless? I'm assuming there are other wireless connections in your home? Otherwise I'd suggest unplugging it just to see if maybe it's somehow related to the problem. It's very unlikely but hey, weird stuff happens.

 

[woomera]

thanks for replies guys.
@lantz,
yes some devices like my iPhone sometimes using the wireless access.

after 2 days struggling with this found the solution. yes when the pc was turned off the transfer between laptop and xp was slow, so i started by changing the cable connections on the router but wasnt it then i realized if the PC was turned off and i started a transfer the speed was 60-100 KB/s and as soon as i disconnect the pc network cable from router the speed jumps to 11-15MB/s at that point it was clear that even when pc was turned off it must've been sending some sort of signal or something that mess's with the router.
tried changing any option in pc's bios which set's the LAN to listen or send network signals while turned off like WOL.

so the problem is gone for now, really was annoying for 2 days.