Logic EQ not working. HELP!

Everytime I use the Logic 9 pro in-built EQ and add the lower end cut, when i play the track it just keeps cutting intill there is nothing left in that channel, as it has cut it all out frequencies. Its not on a automation to cut it out. It also happens when i open my old mixes and its slightly dangrous as it changes the EQ of any channel I select with the EQ on and overwrites my previous data!

I dont want to reinstall Logic as it takes hours! and i dont have that much time and its to big of inconvience. Please help