I have this same problem. Click on the Servers button (not the arrow) & there is a blank server line at the top of the list. I delete it, then the servers show-up in Manage Servers & when clicking the Server arrow.
On reboot it is there again - so it looks like there are no servers in "manage servers" or on the Server-arrow
I will try the solution posted...

Might just check to see if you have the latest version too. Should be v6.9 Build 2014.
Sounds crazy I know, but you'd be surprised how many times this happens

I'm still seeing a similar issue with all of my host info disappearing at random times.

I'm having upload issues also. Just reinstalled after refreshing Windows 8 and now it won't upload fully. In other words, the files say they are uploaded, but they don't show on the page correctly, very messed up, had to revert to uploading within a different program to complete it and when I did so it worked just fine so something is messed up in the uploader too.

Mine works ok, um, so far ... (knock-on-wood)

Win7, IE10