RPC Server Unavailable

Hi i am having this weird problem.

I keep getting the error RPC Server Unavailable when i tried conecting to the company. It can retrieve the company name into the listbox without any problem. Only connecting it gives me this error.

This only happens to the database in the live server in Windows2003 Server. The patch level for the server is 6.7 and the SDK Sapbobscom i am using is also 6.7 so this is not the version problem. Is there any problem with the server itself? Thanks