Hi,
I'd like to preface this with a cliched disclaimer. I am pretty new to moodle.
I have a series of issues that all seem to be related because they started around the same time within the last month. When I login to moodle it redirects me back to the homepage which is pretty standard. But my administration block is missing and the login button is still available as if I haven't logged in yet. If I click on a course then my block is back and it recognizes that I am logged in except for when it doesn't. Sometimes, instead of recognizing me it will say that I am logged in as what seems to be the last student to access the course. I guess ultimately I don't know if this is an authentication issue, a database issue, or what it is really.
Additionally, to put a hat on a hat, and I don't know if this is related. But my confirmation emails which aren't configured to run through SMTP but rather the PHP code, are not being received by some of my users. If this is related and helps you to diagnose my issue. If it is unrelated and in the wrong section then please disregard, I just figured it might be related because it started happening around the same time frame.
My moodle version is 2.8.1 running on a linuxbox, using the default easy install options from bluehost.