I'm having two problems with Mint 15, 64-bit Cinnamon edition, updated to current.
First, MDM starts OK, it displays the mouse cursor (it even turns into an I-beam in the correct places), but I can't enter my user name (or even select it). Pressing the Enter key does nothing. Going to a command line, killing mdm by PID, and restarting it doesn't help.
Details: I'm using the proprietary NVIDIA driver (from the repositories), version 304. MDM's at version 1.2.5. I put "vga=791" into GRUB's "GRUB_CMDLINE_LINUX_DEFAULT=" line so that I get a proper Mint plymouth logo (yeah, I know using "vga=" is deprecated, but it still works).
I installed and configured lightdm in MDM's place, and it looks great and all (see here and here for exhaustive instructions), but it installed a bunch of software (parts of Unity) that I don't need. I'd like to go back to MDM.
Second, the majority of the time (probably 80%) I start Chromium, it ends up in a little window in the corner, as in the attached screenshot. Cinnamon thinks it's maximized. Closing it and restarting it (or just starting a new instance) usually gives me a full-screen window.
Any help would be greatly appreciated. Otherwise, Cinnamon rocks.