I downloaded the 5.1-rc build to test out, and I found that the title bar was effectively transparent with regards to mouse clicks in fullscreen mode. Visually it blocked out the desktop and other windows behind it, but if I were to click on it the mouse would pick up files on the desktop rather than be captured by the homebank window. The same goes for the minimize/maximize/close buttons; they are not able to be clicked. The attached screen shot shows this, where I've clicked on the title bar and have managed to hold onto a file on my desktop.
I also found that if Homebank 5.1-rc was closed in fullscreen mode, and then started up again, it does not render the window after asking about the currency. I am only able to make it show up by alt-tabbing to the window and using the Windows+arrow keys to make it smaller, at which point it would render the window.
After trying out the release candidate I reverted my installation back to 5.0.9, and I started having fullscreen issues with that as well. I have two monitors, and Homebank 5.0.9 would not properly render on my primary monitor on fullscreen, just showing a title bar and a white window. It does not respond to my mouse; again I was only able to make it render properly by alt-tabbing to the window and using the Windows+arrow keys to make it smaller. Only on my second monitor does the fullscreen mode render properly. I did not experience this issue with 5.0.9 before; only after reverting back to it after trying out the 5.1-rc installation.
Managed to get 5.0.9 working again by uninstalling Homebank, manually deleting the installation folder that was leftover, rebooting and then reinstalling 5.0.9.