Yeah, really weird. Certainly wasn't any property I could spot.

If I stopped the code with the debugger, and popped 306 into the value field (via the debugger) then the text property would change correctly (again in the debugger). However the text wasn't being displayed in the actual control on the form. The control itself would just show null. I deleted the control from the form and added it back in with the same code and everythign worked as expected. I beat my head on this for days though so would love to know what was going on.

 To clarify the behavior I have the

dropdownstyle = dropdownlist
limittolist = true

In the debugger if I set the value to 306. The Text says ENZN which is the correct value, but it doesn't go ahead and select the row, so the dropdown still shows the null value. If I click on the dropdown it opens and ENZN is the first item, i.e it's scrolled to the correct spot in the list. But it just doesn't show it when the dropdown is in the closed state.