Weird phone line problem...

I am experiencing a very weird problem.

Firstly, there is no problem with my adsl line...

I used a Siemens CL-110 modem-router and no speed problems.

When I changed it to a Thomson TG585 v8, problems started...
Low speeds, unless I pick up the phone.....
When I am speaking to the phone or just pick it up, speed comes back!

Line voltages are:

48 Volts when phone is resting

-20 volts when ringing

8,44 Volts when I pick up the phone or speaking.

Thanks in advance for any help!

It sounds like you may have a bad or mis-wired DSL filter.

The folks over at www.dslreports.com should be able to help you out.