(shift f2) stopped working on XFree 4.3

After I've switched to XFree 4.3, cusomized key bindings that use a
combination of SHIFT and a function key stopped working.

For example if I press Shift-F2 after evaluating

(global-set-key '(shift f2) 'delete-indentation) 

I get "f2 not defined." in *Message-Log*, so it seems as if the Shift
key is not recognized.

The key binding works as expected under XFree 4.2 so I wonder if this
is some kind of bug and if other people see this behavior as well.