I assume you have in mind the mouse wheel button of the mouse. If this is the case then I wasn't able to reproduce the issue you describe. Please find attached my sample project. Have a look at it and let me know if I am missing something. I'd be glad to further assist you.
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items