I'm confused! The Auto Expand Property refers to the cbo's ability to move to the first matching selection vis-à-vis each character you type into the box...and, by default, is set to Yes.
The List Rows Property refers to how many selections are displayed when the Combobox is 'dropped down,' and it default to 15 or 16, if I remember correctly, but has nothing to do with entering data into the box.
In plain language, what you are trying to do, here?
Linq ;0)>