Have you got a DoEvents in your file processing code? If not your code is probably locking out the timer event.

I generally prefer to do my own periodic update using an internal counter within the loop as I've found the overhead on frequent timer calls slows down processing too much.

lnUpdateCount = 0
Do while Not Feof()
lnUpdateCount = lnUpdateCount + 1
if lnUpdateCount > 100 && or whatever value keeps update progressing
&& without slowing down processing too much
Thisform.UpdateProgress(lnUpdateCount-1)
&& so I'm telling them how many records have been processed
lnUpdateCount = 1
endif

*-- then on with the real work
Enddo

Best regards

Andrew