MultiSelect Listbox items suddenly are transformed to null values

[Dave Worthy]

I submitted this a couple of days ago but it hasn't yet shown. So I'll try again.
This error occurs on one computer only. I've tried to recreate it on two other computers to no avail.
I am using a multiselect list box with one column and 18 rows, containing dates of shows. Selecting or deselecting items result in AfterUpdate actions of adding or deleting reservations. It will work a random number of times and then suddenly all list values are transformed to null values.
I've reinstalled Office 2000 running under windows 2000 and applied all available updates to Office 2000.
It appears to be localized to the computer, but I don't think it can be a machine generated problem.
This is weird and I'm confused. Can any one share some insight.

 

[Wadester]

How do the reservation additions and deletions happen? Can you post some code?
What is the list box based on?
With some more information you might find some help.

I submitted this a couple of days ago but it hasn't yet shown. So I'll try again.
This error occurs on one computer only. I've tried to recreate it on two other computers to no avail.
I am using a multiselect list box with one column and 18 rows, containing

dates of shows. Selecting or deselecting items result in AfterUpdate actions of
adding or deleting reservations. It will work a random number of times and
then suddenly all list values are transformed to null values.