asp.net lock grid when checkbox selected

I have a grid that includes a checkbox control with Autopostback=yes and CheckChanged calling a routine in the vb.net code that updates the record with the checkbox value. When a checkbox is clicked it takes a second or two to run the code and return control back to the web page. I have some users that are clicking several checkboxes one after another so the program is not being called correctly and they are getting a hodgepodge of updated records. For now my solution is for them to wait until the page refreshes before they click the next one. Pretty lamo. Does anyone have any suggestions to work around this problem?

Thanks!