ok try this: open vstudio make sure fileview in workspace pane is open and some files with long filenames are visible in fileview (so that some of them do not fit in the view) leave alone mouse;) while in editor, press alt+0. this makes active windows to file view with keyboard arrow keys select a long file (which doesn't fit there), so that the blue rectangle (selection) intersects and above the vertical scroll bar of the fileview. press ESC. this moves cursor to the editor window again. press ctrl+f4. i'm sure an interesting bug is hidden there;)
which IDE are you using? with .NET 2003 i have the "solution explorer" which shows me the files in my project.
for me the default key to put focus here is CTRL_ALT_L. doing this i am not getting any tooltips when i move the current item up and down the list with the keyboard, but i do get them if i hover the mouse over one of the items.
having done something as close as i can get CTRL_F4 works as expected for me.