Dashboard disappears

Nope. Random occurances on the back-end are almost impossible to debug.

Is there an error message? What happens exactly and when? Is it just a white screen? When does it come back up and what do you do to make that happen? Does it happen with all browsers, on different computers, on a different network? What is the url?

Likewise I seem to have a helluva time signing in anymore. It doesn’t want to recognize my password. Tried new ones, and same thing?

Using FF?

The normal protocol is to disable all plugins and restore one at a time until it breaks and to also revert to the twentyeleven theme to rule out a theme problem. You also want to validate the code to see if there are any important problems. You can run FireBug or IE’s developer tools when going to the back end to see if they uncover a problem. Just not being there would be a javascript conflict most likely so the loading stops.

You can also delete the wp-admin and wp-includes folders. DO NOT bother with the wp-content folder. Download a new copy of 3.4, extract those two directories and upload them to the server.