The !"#¤&:s at Dovetail Games have made a change to fsui.dll that makes the homescreen rather than the last used screen be loaded when you start FSX. This infuriates me, since it's only there for them to push their advertising in a game I paid for, and it's very annoying to have that screen load, and have to click your preferred screen everytime you start the sim. But if you replace the fsui.dll with the older version i post here, you will regain the functionality (remembering last screen used) that FSX used to have. Enjoy!
[Link removed, sorry guys. FSX DLL's are technically copyrighted and not allowed for redistribution. Not a risk I want to take with the message board. -- Dan]