Hi Aaron,
After looking into this more this was actually a problem on our end. You should be able to use Google Chrome going forward and I believe that due to a cookie issue you just happened to see the problem in Chrome but not other browsers (we have multiple API servers which can cause that type of behavior sometimes).
We have cleared these issues up as of about 5 minutes ago. Let me know if you see any further problems.
Dave Berard
Senior Product Manager, Constant Contact