Activity stream returns 401 error intermittently

Problem

The Activity Stream on the Dashboard has been randomly failing to auto-refresh. Sometimes it just goes blank, and other times it has an "Unauthorized 401" error in it. Ctrl+R brings it back to life.

Environment

Dashboards
.

Steps to Reproduce

Open a dashboard
Add the activity stream gadget and configure to show some data
Set to auto refresh every 15 min.
Wait for some unknown time and it returns a 401 error.

Expected Results

The activity stream should load the data, instead of returning a 401 unauthorized error.

Actual Results

Should show the data on the activity stream

Workaround

Have to manually auto refresh it

Notes