Hello,
Can you please provide any specifics?
What actions are you taking between clicking menu entires?
Are you waiting for the previous loading to finish before the next click?
Can you please check for any JS errors that may occur? (firebug helps track this)
Can you check if all ajax requests finish properly? (firebug helps track this)
I'm sorry to say we didn't encounter such problem ourselves, while using the software on daily basis.
Kind regards,
Arek