TAdvFindDialog strange behaviour

Hi, we are using TMS Component Pack 8.6.1.0 and have noticed some strange behaviour when using TAdvMemo with TAdvMemoFindDialog and TAdvFindDialog. The first search using TAdvFindDialog works fine, but then if I delete a character from the search string the "Find" and "Previous" buttons become disabled.  Then when I type another character the buttons become enable again.  Is this a bug or some strange option I haven't found?
Regards, Robin.

I have retested this here with a TAdvMemo, TAdvMemoFindDialog & TAdvFindDialog connected and using AdvMemoFindDialog1.Execute but I cannot see a problem here. The buttons never become disabled here. 
If a problem persists can you please create some sample source project and send this with step by step instructions to reproduce to support by email.

I have tried a test project but am unable to reproduce the error so
far.  However I have noticed that the buttons do become disabled when
there is no search text.  This is logical, but seems to
indicate that there is something keeping track of the number of
characters in the search text, so maybe in some cases this becomes out of
sync with the actual text.

I will try extracting the problematic form from the real project and see if I can trigger it that way but this may take a while.
Regards, Robin.