Question
Has anyone encountered issues with portal users suddenly being asked to login again to the customer portal when accessing Visualforce resources? Any ideas what could be done to fix it?
Background
We have a customer portal with some helper buttons that are implemented in Visualforce and then displayed to the user via an iframe in a custom sidebar component. For some users, using the buttons in the sidebar component takes them back to the login page. Based on the startURL param from the login page the referring page was /visualforce/session?url=https%3A%2F%2Fc.na1.visual.force.com%2Fapex%2FMyVfPage
.
It would appear the sequence is
Login to the Portal land on home page
Click Over to a Visualforce Page
Get redirected to /visualforce/session
/visualforce/session?url=https%3A%2F%2Fc.na1.visual.force.com%2Fapex%2FMyVfPage
Kicked out to login page