Strange band at the top of laptop screen

[joeyh51]

I have a strange band at the top of my laptop screen, I've attached a screenshot:


image host
It's since I've started using an external monitor, and it goes when I open up full screen programs, its just when I have windows minimised that it shows up. Any ideas what it is?

Laptop spec is Sony VAIO S Series SA3T9E:

Intel Core i7 2640M
4GB RAM
Intel HD Graphics 3000 & AMD Radeon HD 6630M
128GB SSD


EDIT: It looks like its a chrome window thats opened and left a shadow of the image across the top of the screen.

 

[Disco Boy]

If you reboot, does it come back?

 

[joeyh51]

Yeah its been there since I set the laptop up with the monitor.

 

[joeyh51]

No one have any idea what this could be? It's really really annoying!