I have never had this problem in other versions. But in Maple 12, some search topics (sum, add, for instance) are guaranteed to lock it up. In addition, after a short series of HELP searches, the search operation locks up. It sems to be inevitable, search enough times, and it locks up. At the suggestion of Maple staff, I uninstalled and reinstalled Maple 12. It did not help.
It may be some unique peculiarity of my particular home computer, but the effect is the same. I cannot depend on Maple12 HELP search. I am forced to run Maple 11 concurrently, and use that search. I am exasperated with Maplesoft apparent disinterest in my problem. If Maple 11 is the only reliable version, why should I keep up with later versions?