Run Gimp in one window
Here is a command line to run Gimp in one window.
Open a Terminal and copy+paste the following line:
Xnest :1 -ac -name GIMP -geometry 1024×690 & metacity –display :1 & gimp –display :1
Make sure you have xnest installed.
If you don’t have xnest installed open a Terminal (Applications->Accessories->Terminal) and type the following line: sudo apt-get install xnest