Thank you very much for the reply.

I have waited a couple of days before replying to you and made the adjustments you suggest.

Since then I continue to get the sudden disappearence but am willing to agree it may be the junk files.
However, what concerns me is why, after I search again (get more results), I seem to have less files than previously. May be I have the wrong idea but to 'get more results' is supposed to add to the previously found files and not remove some.

Thanks again for the quick reply - I would appreciate more help on this matter

David