Download Stops At 20.088 Mb With Java Clients !!

CAN ANYONE SOLVE MY PROBLEM...everytime i try to download a file more than 20 mb with toonel.net client {www.toonel.net} it stops without any reason !!

toonel.net is a java client ...and i have this problem with every clients which use JAVA !!

but,its 10 days now that i have this problem...and befire this,it was working great....!

i contact to toonel.net admin and he says that we dont have file size limit on our program!!

i also tried this with vista {and i dont install anything on it too!!}
but it didnt work there too!

here is the image of waht happend!




PLEASE HELP ...YOU WILL BE MY GOD IF U DO!!!
TNX.