Internet drops when telephone rings

Hello,

Problem:
when the telephone rings my internet connection drops.

Architecture:
-Uniden - DECT 2035 + 1 - Digital Cordless Phone System. It is plugged into an adsl 2+ filter/splitter (located in the living room).
-Modem netgear dm111p connected to an adsl2+ filter (located in the studio).
-Router linksys wrt610n v2, connected to the modem. (located in the studio).
I have a computer and a NAS plugged to the router and a led tv connected via wireless with no issues at all.

I will appreciate any help.
regards,
max