I ran your project and I successfully created and edited appointments in the advanced form without any freeze in the Advanced Form.
However I suspect that maybe on your production server some scripts are not loaded correctly.
Could you please tell me whether you got the same issue with our "Advanced Templates" demo
as I am not sure how to reproduce the issue on my side?
P.S: I saw that your Advanced Form looks transparent. This is a known issue and you can see how to fix it in this sticky forum post
for Q3 2010
the Telerik team