I had this problem too...

Your problem occurs because when you set some mod in Maemod it changes the config file and remove the CSSU functions... (thp_tweaks... I think that's the name).

If you ever upgraded CSSU, you probably have a backup file that's created automatically...
/usr/share/hildon-desktop/transitions.ini.old

To recover the .old file just type in terminal
mv /usr/share/hildon-desktop/transitions.ini.old /usr/share/hildon-desktop/transitions.ini

If not, you need the "virgin" CSSU config file...

My file has a lot of configs chaged... If you want a "virgin" one ask the people here... If not that's mine... I think you will love it! Changed the transitions to make the device look a lot more faster..