1. The .text property is only available while the control still has the focus so it is only available in the change event and possibly the click event. I would always use the .Value property for a combo.
2. Keep in mind that you are actually referencing the bound value, not the value that is displayed.
3. When the data in subformB depends on a value on formA, use the Current event of formA to control the visibility of subformB.
4. If the bound value is not the visible value, you need to reference the .Column property of the control to compare the string to the text value of the combo's RowSource.