Thank you for writing.
In Q2 2011 we had completely rewritten our RadDateTimePicker/RadMaskedEditBox controls in order to fix a few shortcomings and we have added the below mentioned property which allows you to disable the mouse-wheel functionality. However, in Q2 2010 such an option does not exists and I am not able to provide you with a replacement due to the internal implementation of the control in Q2 2010.
I would like to suggest to upgrade to the latest version, where can access this property and take advantage of this functionality.
Do not hesitate to contact us if you have other questions.
All the best,
the Telerik team