not in sync error when ethernet shield is connected

Hi all, run in some trouble here. I'm using a DCcduino witch i've bought here, on the back it says DCcele DCcduino and an ethernet shield bought here witch has the markings HanRun HR911105A 14/31 on it. i've done some projects on the arduino without problems but when i connect the shield all my uploads fail with the message 'avrdude stk500_getsync() not in sync resp=0x00'. i tried a different com port (worked when i got this error sometimes without ethernet shield connected) but that didn't change anything. Am i doing something wrong or is the shield crap or something? Any advice is welcome at this point ! Thank you !!