WDTV Live box is being recognized as a 10/100 speed device by my router

If the movie size is only 10GB, why not get a cheap 16GB USB Flash Drive from Walmart or someplace similar (if you don’t already have one)? You should be able to get one for less than $20 if you look around.

Put the problematic file on the USB Flash Drive and plug it right into the WDTV and see if it still has issues.

If you are like me, you could always use an extra USB Flash Drive anyway.