VFP8 SP1 on XP Pro SP2

I have some code that was running a bit slowly:

 SELECT DISTINCT colToFix ;
 INTO ARRAY colArray ;
 FROM myTbl

 SELECT myTbl
 FOR EACH curVal IN colArray
   lcNewVal = ThisForm.Standardize(curVal)

   REPLACE colToFix WITH lcNewVal FOR colToFix = curVal
 ENDFOR

There is an index on the ColToFix column.  myTbl is a
free table.

Standardize is a method that makes sure the passed in
value follows certain formatting rules.

On a table with 50K records, this was taking almost 2
minutes.  There are about 10 distinct values in the
column in question.  All of the execution time was
happening in the 10 calls to REPLACE - some of them
taking over 20 seconds!  With such a small table and
indexed on the column in question, I would think
each REPLACE would take no more than a second.  I've
tested on many, many tables of the same size with the
same result, so it's not a corruption issue.

Playing around with it, I changed it to the following:

 SELECT myTbl
 SCAN
    REPLACE colToFix WITH ThisForm.Standardize(colToFix)
 ENDSCAN

Amazingly, this was 5 times faster!  How could performing
50K replacements and 50K calls to the standardize method
take *less* time than doing 10 calls to each?!?

This was also 5 times faster:

 SELECT myTbl
 REPLACE colToFix WITH ThisForm.Standardize(colToFix) ALL

I rarely have performance problems in VFP, so this one's
a bit of a head scratcher.  Any ideas on why this difference
and how to possibly make this run even faster?

-- TRW
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t i m  .  w i t o r t
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