Erratic USB mouse behaviour when wireless is down and USB hard disk connected

Hi,

I know that this is not a very helpful information.

I have an Lenovo X220 running 10 from some 2 weeks ago. I just noticed that 
the USB mouse (a wireless Logitech Trackman) becomes unusable when the 
wireless (iwn) is not able to connect to the access point and a USB hard disk 
is plugged in. Even when no data are transferred the USB mouse is unusable.

The built-in track-point behaves just normal.

When I turn off the wireless network via the hardware switch, the system stays 
usable as expected even under heavy hard disk access. If it was not something 
else I have missed, the only difference was the access point which went down 
when I noticed the problem.

Please understand this just as a hint to the developers of the sub-systems 
which could cause the problem. As this network here is not mine, I am not able 
to do any tests with it.

If somebody has an idea what could be tested, tell me please. I will have 
access to 'my' network the coming week again.

Erich