Empty combo box, sometimes

  • Thread starter Thread starter Jim K
  • Start date Start date
J

Jim K

I have an application that I originally created in Access
97 and have migrated it to Access XP/2002. I have created
runtime installations in both versions, and they ususally
work correctly.

Sometimes, however, when I install the XP version on a PC,
the combo box on the login screen is empty. The row source
is data from a linked table in a 97 .mdb file on our
network (both runtime versions are used concurrently and
access the same back-end data).

The only condition that I can find that causes this EVERY
time is installing on Windows NT 4. On Windows 2000, I
cannot determine what makes it work on some machines and
not others. I have tried un/re-installing and it makes no
difference. I have updated the PC to MDAC 2.8, no effect.

Any ideas?

Jim
 
There are a couple of reasons why a combo may fail to display correctly.

One is when the form has no records, no new record can be added, and the
combo is in the form header or footer section.

Another is when the bound column is zero-width, and the RowSource is
assigned dynamically.

Description and example at:
http://allenbrowne.com/bug-06.html

Hope that helps you pin down this frustration.
 
Thanks Allen, but that's not the problem.

The form is a switchboard that I've modified heavily. The
data source for the form is "Switchboard Items" and it
works correctly.

I have a combo box called "cboUserFinder" on the side that
reads a table with the user names and passwords. The
password is column 2 and is bound but 0" width, the name is
column 1 and visible. The row source is hard coded, a query
called "cboUserFinder".

If I install the 97 version on the same machine having
problems with the XP version, it will work, and it's
reading from the same back-end data file. If I install
either the 97 or XP version on a different PC, they'll both
work fine. It's the inconsistency that's causing the
problem. I already know that the XP version doesn't like NT
4, so I don't even bother with it on those machines, but
the XP version has a utility section specific to it and
some people need to have it, so just giving them the 97
version doesn't work (and the utilities don't work in 97).

Any other ideas? Thanks for the link! I'll be going through
your tips for sure!

Jim
 
Okay, Jim. We need to eliminate the other known problem areas first.

1. Name AutoCorrect is off? (Tools | Options | General, under Access 2002).
This is the source of many bugs:
http://allenbrowne.com/bug-03.html

2. Row level locks is off? (Tools | Options | Advanced). This is a slight
but potential issue since the back end is A97 and Jet 3.5 does not support
it.

3. Service packs. Will involve both msjet40.dll and msjet35.dll. Typically
in windows\system32, though you need eliminate the possibility of duplicate
dlls (esp. with 3.5). Should be at least 3.51.3328 and 4.0.8015.0
respectively. Updates from support.microsoft.com under service packs.

4. Opportunistic locking on server is off? Details:
http://support.microsoft.com/?id=129202
http://support.microsoft.com/?id=296264

5. Verify the settings for lists under:
Tools | Options | Edit/Find | Filter by form defaults

After that, it would be good to devise a way to determine whether the
problem is with display (i.e. the value is there, but not shown), or
retrival (i.e. the value is not present. A Debug.Print may show that.

If the value is not being retrieved, does it work when the data file is
moved to the local hard disk? If so, it's in the realm of a network/server
problem, not an Access problem.

Again, hope this helps to at least narrow it down.
 
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