Thank you for contacting us.
I confirm that this is known issue with our RadScheduler. The issue is observed in themes Office2010Black, Office2010Silver and Office2010Blue. We already have it logged in our Feedback Portal
. You can track its progress, subscribe for status changes and add your vote/comment to it on the following link - Feedback Item
Unfortunately, due to the nature of the issue I cannot provide you with a workaround for it in version Q2 2014. The issue was fixed in Q2 2014 SP1 (2014.2.715) and one way to avoid it is to upgrade to the latest version.
Hope this will help you. Let me know if you have any another questions.
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