Sounds like you have triggered an endless loop here, so the form is
constantly recalculating or requerying the data.
If you are using Conditional Formatting on any controls, you might try
temporarily removing it to see if it helps. This is particularly a problem
for controls with a calculated expression in the Control Source, and the
issue is worse in Access 2000.
If that's not the case, see if you can track down anything in the events
that could trigger an endless loop. For example, if the subform's Current
event requeries the main form (or recalculates it), the main form might
respond by reloading the data for the subform to ensure it is up to date
with the new data. Naturally, when the record is loaded into the subform,
its Current event is triggered, and that code affects the main form again,
Allen Browne - Microsoft MVP. Perth, Western Australia
Tips for Access users - http://allenbrowne.com/tips.html
Reply to group, rather than allenbrowne at mvps dot org.
"colin spalding" <email@example.com> wrote in message
> When I display the form, the screen flickers, the hourglass flickers
> on and off, and the taskbar displays 'Calculating'.
> The form is quite complex with nine tabs and seven subforms. but the
> problem only occurs in certain records.
> I have tried other suggestions suggested by the group, ie installing
> Service pack 3; and changing unattached labels to text boxes, both
> without success,