audio input problem

hi guys!
I am working on a patcher using audio input and i am having a little annoying problem with that. no matter which patch i am using (it can also just be the audiotester example…) i always just recieve audio input the first time i open a patch or bang the adc. if i switch off the adc and switch it on, i will not recieve a signal again until i restart the whole max-runtime….?!?!?!? anybody got the same problem?? or does anybody can give me a solution???
thanks