On the Mac by default floating windows like the toolbar disappear when the application isn't front most. This is true of all Mac applications: Photoshop is a good example - all the floating windows disappear when Photoshop goes into the background.
We originally shipped QuickBooks Mac with that behavior. But we discovered that users coming from Microsoft Windows would get confused. They'd close all the QB windows except the toolbar then switch QB into the background. When they did that the toolbar would disappear. Coming from Windows they thought this meant the QuickBooks application had quit. They'd then post here asking what happened to QuickBooks?
So... prior to R6 we had an option to keep the toolbar visible when QuickBooks wasn't the front most application. To do this we had to hack the standard Mac OS behavior. But it solved the issue with Windows users new to the platform. Unfortunately the hacks had a detrimental effect on other Mac OS behavior - in particular sometimes QB would lock up if you clicked on the Finder. It also caused problems with the Desktop Spaces feature of Mac OS.
To fix those issues we had to remove the option for the toolbar to stay visible when QuickBooks is in the background. It now is only visible when Quickbooks is frontmost - just like all other Mac OS applications. We just couldn't get it to work reliably bucking the OS default behavior. Sorry.
