Photoshop CS5 Border - How to Remove?

I have just upgraded from Photoshop CS3 to CS5. I like most of the new features however there is one feature that I do not like.

When opening an image there is a very large grey border outside of the actual image area. For example with a with a magnified area if the the 'Hand Tool' is used this border also drags into the working area, which I find very annoying.

This did not happen in CS3, so is there an adjustment to remove to remove this border?

no sure what you speak of, can you post a screen shot maybe some will have an idea for you

It's a job to explain and it's probably something stupid that I cannot work out.
Going by the screen shot the red cross hatch area is the problem. With CS3 this area was not there, it was a tight fit (image only and no grey board area). It's noticeable when using the hand tool.

tried to duplicate that, sorry I couldn't
I can only suggest if it only shows when using the hand tool , to reset the hand tool, see if that helps.very strange

I found the problem, it was a setting in the preferences.
Setting changes required
uncheck 'Open Documents As Tabs'
uncheck 'Enable Floating Documents Windows Docking'

HMMM I still do not get those lines. your shot looks like picture on a picture to me not the outer parameters

The main problem was that there were no scroll bars on the frame of the image, The red cross hatch marks were just to show where the problem was, sorry if I have mislead you.
Any way the new screen shot layout is below, which is the same as my previous CS3 version.