going down the painful way of upgrading your app from rails 2.x to rails3? one of the gotchas can be that suddenly you find B helper's X method running when you normally expect A helper's X method to run...
I get this problem each time I do a distro upgrade on my Ubuntu box; mounting external USB harddrives end up in a "Not Authorized" message box. This is -- like it was in Karmic Koala - a policy issue, but fix is slightly different...