I have instances of using OnClientBlur on multiple RadComboBox controls, and if you tab quickly enough the event does not fire.  I've created an example which replicates what I see in the project I'm working on - two RadComboBoxes with the Blur event where I get the second to fire but not the first when tabbing from first to second to third (just another control w/o event).

This is causing issues where some validation is bypassed.

Screencast: http://screencast.com/t/VTQrN9uOVrI9

A couple observations:
- It will fire correctly if I wait long enough before tabbing out.
- If I pause on the second control after tabbing, then click somewhere, it sometimes then fires the Blur from the first control.
- I am using LoadOnDemand.  From my general observation it looks like it's potentially a race condition with the loading.