Problems with external display

[GrantR]

Hi,

I have an early 2011 MacBook Pro and have just baught a Samsung ku6400 tv to use as an external display. Films play perfectly fine but the look of the os is off like the resolution is not correct images look sort of cartoony? Has anyone got any ideas how to fix this?

 

[orph]

is the resolution set to the tv's native resolution ?
sounds silly but worth asking