Small image on client PC. Any ideas?

[Jax Boom]

ISSUE
The image produced on the client is a small version (Approx 1/4 of full screen) placed in the top left corner of a black screen. All on-screen infomation is in the right place (as in at the bottom left of the screen) but the streaming image is tiny and stuck up in the top left corner. When using a mouse i have to click on the screen where the clickable option would be if the image took up the whole screen. This is driving me mad. Any help would be amazing!!

OS
Windows 7 64

SYSTEM
Host
GTX 770
Phenom 2 x6 2.8Ghz
Dual band wifi card on 5ghz @ 450Mbps

Client
Acer revo 3700

STEPS
Both pcs up to date
streaming enabled
Hardware encoding options tried on and off
select stream on game on client
Games tried - Dirt 3, Borderlands 2, Skyrim.

RESULTS
Stream starts. But only black screen with inlaid image in top left corner. It works fine to play but is a miniture version of the screen on the host PC.

F6 shows - Beta streaming 1280 x 720 capture @ 58.xx

EXPECTED
Full screen version of host.

Amy one know whats going on? Hopefully its just a setting i havn't set properly....

[UnReal-4-Life]

wifi / windowed /client grapics is set to screen size and is tiny card./ client is amd or ati and a laptop. / Client is not steamOS beta any of those named would do it.IMO just not very much info . I would try wired first and go threw it one at a time..

[Jax Boom]

Ty. Turned out the graphics driver on Acers website was out of date. All sorted now! Lovin it!