Elusive indentation problem in CC Mode

[Eli Zaretskii <eliz@gnu.org>]

From time to time, I have a strange Heisenbug when editing C source
files: CC Mode computes the indentation level incorrectly.  The
problem usually manifests itself by pressing TAB and having the
current line be flushed all the way to the left, as if point is at
toplevel (which it isn't).  I know it thinks point is at toplevel
because that's what "C-c C-s" tells me.

The "Heisenbug" part comes into play when I try to figure out which
part of the buffer causes the problem, by selectively deleting some of
the parts around point: after a few deletions, restoring the deleted
parts exactly as they were makes the problem go away.

This is in Emacs 24.0.94.  Is this a known problem, and if so, was it
already fixed since 24.0.94 was released?  (Since I don't have a way
of reproducing the problem, I cannot test this in the current trunk.)
If not, I will file a bug report, and please give me instructions for
digging into the problem next time it happens, preferably without
modifying the buffer (which seems to make the problem hide).

TIA