MS Access Error "command or action 'saverecord' isn't available now"

[ccasei01]

I have this MS Access XP Database (but it is saved as Access 2000) where
I perform a number of queries to prepopulate certain fields in forms
and then the rest of the fields are manually entered. Everytime that I
try to create calculated fields to be done via the query (as opposed to
calculating them within the form fields), when I open the form I get
this error message "The command or action 'saverecord' isn't available
now". Then, I am not allowed to enter information. The forms,
typically have a subforms.

For example, there is the header table that contains a customer's info,
while a subform tracks each payment. The info in each form is comming
from different tables. See a sample code that I created to have the
customer's form count the number of payments that the customer has
made. PLEASE HELP! HOW DO I GET AROUND THIS? I AM NOT RUNNING VBA
CODE.

NOofPMTS: (SELECT Count([Accounts Receivables].[TrasactionType]) FROM
[Accounts Receivables] WHERE ([Accounts Receivables].[TrasactionType]=
"Pmt" AND [Sales Order].[SalesOrderID]=[Accounts
Receivables].[SalesOrderID]))

Carlos....