Nath,
How old or new is your CH stick and throttle?
If you have had them for a good while and used them a lot, you might need to open them up and spray the parts and pots with some non-conductive electrical cleaner ... CRC makes a good version of this... Drano just did some cleanup & preventive maintenance on his recently... You can get the cleaner at radio shack, Lowe's, Home Depot, maybe even Walmart... Their are other brand names of it besides CRC
also I agree with what Del and Fugi posted
Hope this helps...
TC