Query runs fast once, then very slow

[Rog]

I have two append queries that each append records from an SQL table
into a temporary Access table in the frontend. All of a sudden one of
them has become very slow - it takes a minute before the "you are about
to run an append query" is displayed, then several more minutes to
append a few hundred records. I recreated the query, but the result is
still the same. Strange thing is that when I rename (or recreate) the
query, so that it's decompiled, it runs fast the first time, then slow
again the next times it is run. Any ideas?

Thanks,
Rog