>>I would bet that is an index problem, try recreating them.
>
>what do you think would cause an index to do that?
>because the whole process works on one machine, and not the other

I've seen cases when the index gets corrupted and then either the loops end prematurely or worse it enters an infinite loop, and if the second happens when updating the table, it keep always updating the same record over and over.

That been said, now that I re-read, I understand that is the same table different machines, I thought it was different clients running the same program, do not ask me from where did I get that...