The same here. http://forum.tp-link.com/showthread.php?83298-WDR3600-wireless-printer-problems&p=169358&viewfull=1#post169358

It is a comapatibility issue which has not been fixed yet. The temporary solution is to downgrade your MAC OS if you still want to enjoy the printer server function. Or you may wait for the update of...

SSIDs for 2.4GHz and 5GHz band are different in default settings. You should confirm if your wireless clients support dual bands or not. If wireless cards on your clients support 2.4GHz only, they...

You may contact your ISP to confirm if there is any limitation on their end.

If you don't remember username and password for internet connection, you have to confirm with your ISP. It cannot be accessed via SSH. Hard reset is the only way to log in the web interface.

Did you read the user guide? The switch has no access control feature. http://www.tp-link.com/resources/document/TL-SG105E_V1_UG.pdf