The reason the Dispatcher is checking the LoadSheet and signing it is to stop things from going tits up in the first place, trust me, if there is a problem with the Load sheet and you havn't check it correctly then the Dispatcher is ultimatley to blame, from past experiences, if the captain receives an incorrect Loadsheet then the blame will be on the Dispatcher Not the Load Controller, because it shouldn't have got as far as the captain if that was the case, the dispatchers role without any doubt is to make sure that all a/c he/she does are SAFE and this means checking checking checking and double checking everything again and this means countersigning Loadsheets, each company has their own legeslation when it comes to the procedures of a Dispatcher but evey companyshould have the same procedure of SAFTEY.
CHEERS!!!!!!!