subform not working

[ermcc]

First let me explain what I am trying to do:
1. I have a combo box with CustomerID and several other fields in a table called Customer.
2. I also have several records with the same CustomerID but with other fields in a table called Complaints.
3. I would like to select the CustomerID from the combo box, and have all the records from Complaints show in a subform.
4. Then I would like to select the Complaint and populate several fields on different tabs within the same form.
Note: All the Complaint information is on the Complaint table.

I tried using a combo box in my main form to run a query that creates a table with specific information from the complaint table.
This is working perfectly. Every time I select a different item from the combo box it automatically updates the table with all the records.

The problem is, if I try to insert the subform back into the existing form, when I change the combo box, I get an error "The database engine could not lock table 'combobox' because it is already in use by another person or process."

Will this work or am I going about this all wrong?

Thank you...

[June7]

Not familiar with that error. Want to provide db for analysis? Follow instructions at bottom of my post. Identify which forms are involved in the issue.