Photoshop is a nightmare for this.
In the office, I connect my macbook pro to a cinema display but not at home. Switching between dual and single displays seems to cause some software – especially photoshop, filezilla and excel – to move their windows off screen. You can’t grab them to move them around so they are stuck out of reach.
There are some fixes for this.
Option + drag
If you can grab the edge of the application you can hit option and drag. This will resize both sides at once and might be enough to get things back into view.
Spectacle is a handy, open source app which lets you resize windows using keyboard shortcuts. I recommend running it in the status menu (this option can be set by pressing the ‘ > ‘ bottom right) at startup. If the keyboard shortcut doesn’t work then you can access the resize options from the spectacle icon in the status bar.
Spectacle is good – especially for a free app but if you want more, try SizeUp, its not free but it is cheap and adds things like padding to avoid shadow overlap.