For the same reason Yacht & Sail no longer work on most EMUs, but as it not worked since 26.3.09 can you honestly say channel that important to you as your only asking about it now over a month after it stopped working?:
http://www.sat-universe.com/showthread.php?t=113282
Other Motors channels include the italian:
Hotbird 6 (13°E) - 11200V S/R 27500 FEC 5/6 - (Europe Beam, in 4:2:0 SD DVB-S QPSK) "Motori TV"
&
Astra 2D (28.2°E) - 10891H S/R 22000 FEC 5/6 - (Astra 2D Beam, in 4:2:0 SD DVB-S QPSK) "Men & Motors"
And certain other motor sports are on General channels such as Das Erste, ARD, ZDF...any particular event you were looking for?