After modifying two antennas and attempting to send commands to Phobos-Grunt for weeks without success, ESA has made the decision to stop tracking support. In a brief statement posted to their website:
In consultation and agreement with Phobos-Grunt mission managers, ESA engineers will end tracking support today. Efforts in the past week to send commands to and receive data from the Russian Mars mission via ESA ground stations have not succeeded; no response has been seen from the satellite. ESA teams remain available to assist the Phobos-Grunt mission if indicated by any change in the situation.
Time at tracking stations is a finite resource; time and labor spent in fruitless attempts to contact Phobos-Grunt comes at a cost to ESA's own missions. They'd continue if the spacecraft was responding, but since it's not, it's time for ESA to spend its resources elsewhere.