Not issue 1529353.  Edit window stops updating after about 60 
keystrokes when a tooltip window is active.

1. Strings not necessary.  Only occurs when a tooltip is active.  For 
example, if rz is undefined, entering rz( followed by a long key 
sequence won't raise the bug.

2. When the tooltip window closes, the hidden keystrokes appear.  This 
can be triggered by moving the edit window or clicking somewhere. Once 
the tooltip window has closed, things act normally again.

3. Remarkably, one can autorepeat, say, five lines of 'i' with no 
problem.  Then enter another 50 - 60 'i' individually, and the bug 
exhibits.  I thought that typematic processing took place at the 
keyboard driver level, so that Tk would get passed the equivalent of 
single keystrokes.

This bug would be annnoying when entering long parameter tuples, e.g. 
when doing GUI coding.

I'm running Tk 8.5 on WinXP at the moment.   I'm guessing that this is 
a Tk bug.