I don't know about log files from IDE.
Have you installed the latest May patch (you can find it on Getit)? You can also download it on MyDownloads of Embarcadero.
Uncheck the options "Tools/IDE/Saving and recovering/
"Reopen last open project ..."
so the IDE start without loading a project.
P.S.: If you have any third-party add-ons installed, try uninstalling them all and adding them one at a time to see which ones might be causing you problems.