(Sorry wrong forum - reposting) Plugging in Qnap loses connection to internet

[Tortoise]

(Sorry posted in wrong forum, will be reposting in 3rd party hardware)


Hi,
Over the last week I've been dealing with my ADSL providers help desk, swapping wires and generally getting annoyed as my internet connection was no longer working.
I have now got it back, however it looks like the QNAP has been causing the problem.
All was working well until some time last week with Qnap, Slimserver, ADSL and my WinXP PC working reasonably happy together (Qnap connected by cable to a wireless router, everything else wireless), then my internet stopped working one evening.

Now I have discovered that with the Qnap plugged into my router my internet connection fails. This is both with the QNAP switched on & off (with its power lead connected), but if the power lead is not connected to the Qnap then my internet connection is fine.
It is only my internet connection that fails, and I can browse to the Qnap web interface and the routers web interface.

Connecting the Qnap directly to the Squeezebox works ok.

I don't know if this has any bearing, but last week I did update my qnap firmware to the version that has the UnP/Twonky server functionality.

(with the Qnap plugged in occasionally some internet data sometimes gets through - but its quite intermittent and in general unusable)

Has anyone got any suggestions/ideas as to what the problem might be?