Okay, I asked the web host guys and this is what they said:
"Hi Jenifer, we only use single instances of MySQL so the master/slave
replication issue would not be possible. As far as I know, the only way a
delayed update could occur would be if you had multiple updates queued
behind a slow update or any slow query that has left the table locked. But
if that were to occur, I don't think the user of your application would have
been able to advance to the next page of the site since the queries from
them hitting submit would have been hung. Unless you are using timeout
values in your php so after a delay, it gives up and lets the person move on
anyway, and then ultimately the final page is reached while that first
update finally went through."
That's what I had thought.... that the user would have been stuck at that
first page. I'm trying to figure out how a cache could affect it. The
values are taken from the $_POST variable and inserted into the table that
way. When I looked at the order and customer pages, it was after she had
done everything, and I saw the incorrect order shipping address and a
correct account address. I haven't looked at this client's account before
as the company has 40,000+ customers in their database. (a big cudo for
MySQL for handling them so well!)
I think I'll just give up on this one and readdress it if it happens again.
It will probably eat at me for awhile, though, not knowing the answer. lol!
----- Original Message -----
How is your MySQL installation set up? At my company, we have a
master server and several slaves replicating off that master. All
inserts/updates go to the master, and all selects go to the slaves.
We have had some instances where we insert or modify a record in the
master, and request that information from a slave before the
replication has had a chance to complete, so we get old data. Do you
have any sort of setup like that?