Update your settings

Hello
I am having a similar problem. I am trying to upgrade the OS on a MP377 to WINCC Flexiable 2008 from the 2007 OS. The MP377 is currently V 1.0.0 and i am trying to update it to 1.0.5.
All my connections are working correctly and i can backup from the MP377 but when i go to update the OS it sits on the establish a connection then starts briefly and stops.
I get the "Error in interface driver" error.
I have tried with Prosave and have a similiar problem. Currently i am communicating over ethernet.
I know the MP377 is communicating because it changes to "transmitting data" fromt he transfer window.
No matter which way i try and do it i keep getting the Error In Interface driver error.
I have already read and followed all the manuals/walk throughs. 
I have even tried using a differant laptop which had the 1.0.3 OS image and attempted to update from that with the same problem. I have tried a different MP377 and also have exactly the same problem.
Is there any service pack or anything that needs to be applied?
Thanks for the help
Any suggestions?