This is likely just down to how IE handles selections. By clicking very quickly you're going to end up highlighting text outside the editor, meaning you have no cursor in the editor and thus no defined place to insert.
That said, all bug reports will be looked at in time, often in relation to their severity.
I believe this is as my previous post (or similar). It looks like in certain cases IE loses the selection on the editor, which is down to internal handling. When it gets focused, the cursor is returned to the beginning.