Signing on to You Tube on a DVD player

Ok: so while I am a geek about computers and such, I am hopeless around A/V stuff. Don't ask me why. A big part of my brain does not work around it.
I finally got myself a Blu Ray player: Panasonic DMP-BDT220. Setting it up was easy enough.

I went to You Tube and did the Login using my Gmail ID which is what I use to sign in to my You Tube account on my computer. No matter what I did it says, Bad Authentication. I know I have the ID and password right. I can do it that on You Tube directly without a hitch. Can't seem to do this on the TV. What am I doing wrong? can anyone tell me if I can not use my gmail ID to login when you are using these players? Sorry to be daft..

:)

OK : so it finally happened. I guess it was some kind of glitch...but I could sign in to my gmail account and view the YOU TUBE videos I have saved online.
Now: I can't figure out how to adjust the SIZE of the You Tube video screen on my TV. Half the screen is taken up with the You Tube Menu; and I can only view the video itself on the other half. I adjusted screen size on the Vieracast interface (specific to Panasonic it seems) as well as on the player settings --but no go. What I want is "full screen" mode on you tube via the DVD player--but can't figure out...
thanks