Occasional double-letter at start of shortcut

[leesollff]

Occasionally and unpredictably, when a FastFox shortcut expands, the first letter of the shortcut expands when it's not supposed to. For example, I use f for "for", and now and again it expands as "ffor". Or t, which should expand to "the" expands as "tthe". But this doesn't only happen with one-letter shortcuts. Two other examples that come to mind are tt, which occasionally expands to "tthat" instead of the intended "that", and wr, which should be "were" but expands to "wwer".

 

And recently, I've had a problem with u, which should expand to "you", expanding instead to "uyou".

 

Does anyone have any suggestions as to cause and/or solution for either or both of these problems?

 

Thanks much for any information.