But I have no reason to give it that access. This is a Safari 4 thing, I think. It keeps giving me a popup asking permission to access KeyChain for the login details of some internal website of ours. I don't use anything from PubsubAgent, so have no reason to give access, but when I click "Deny", it just gives me the same dialog again. Very annoying.
After some searching, I found the solution by disabling RSS in Safari. I use NewsFire for reading those, so this is a good enough workaround for me.
If anyone else has the same trouble, this is the command to disable RSS in Safari:
defaults write com.apple.Safari DebugSyndicationEnabled 0
If only Apple would add a "Never allow" button to that window, it might be something useful...