My experience that such thing never happens if you use SQL syntax, since it does everything at once. All three lines can be repalced by one, something like

Insert into MyAlias from name thisform.myrecord

>Hi
>I have the following Code:
>Sele MyAlias
>Appe Blank
>GATHER NAME THISFORM.MyRecord MEMO
>
>I have noticed , in a no. of different sites, that in one out of about 3000 transactions, the file is not being updated.
>I have no buffering in the file and have checked the usual stuff, and am also writing to a separate independent file without a problem, with more or less the same data.
>
>The only thing that could be a little bit different is the size of this file
>(Could have 300,000 records +)
>I dont have any buffering on the file, and the only thing that I see is common is that , there would be another user updating this same file at the same time, using the same code as above.
>
>Has anybody come across anything like this (VFP8)
>
>Regards,
>
>Gerard