On each startup, I get the following message in .xsession-errors: "libpager-Message: Failed to set the number of pager rows. You probably have more than 1 pager in your panel setup." I don't have two pagers in my panel... (4.8 release and 4.8 today's git)
This is a FYI warning that setting the pager rows could've failed. Mostly caused when the screen is not ready. Likely related to the same problem in bug #7728.
Neutralized the message a bit.