We recognized the same problem. Sometimes when switching between servers having the domino server tasks displayed or updating with F9 the client goes to 99% CPU load.
Solution: killing all local tasks found to be related to Notes (Process Explorer from Sysinternals is very helpful at this point). And last the Cache.NDK must be(!) deleted - otherwise the problem will occur immediately again.
We are serving Domino servers for several customers so we have to switch many times a day -> the hangs are really bothersome.
Anybody else having this problem or found a solution / work around?
Feedback response number WEBB76WKFT created by Joerg Marheineke on 09/10/2007