Mail Panel settings disappear

I am an avid Opera user for quite some time, but have run into the oddest problem recently. Running the latest non-beta version right now (11.51), and all of a sudden, all my RSS feeds are gone from the mail panel, and the entire mail panel was rearranged to some kind of default (I have a lot of email addresses and had hidden most of them from view from that panel, and now they popped back into view). Trying to change anything in the mail panel only lasts for as long as I keep Opera open. Closing and launching it again, any changes I make are gone.

Then this morning, all my Labels are gone, too, including customized ones and the default ones. Trying to make a new label again only works for as long as the browser is open. Closing it and opening it, the Labels tab is empty again (and in fact set to "hidden", some kind of detault I assume).

Anyone have any ideas what the heck is going on?? I have been really happy with Opera so far, mainly because of its integrated mail agent, but the current state of affairs makes things unworkable. Please don't make me go back to Outlook again, please please please....

Not sure if this is related or not, but I just noticed that under "Preferences->Advanced->Toolbars", whenever I make a change to my Mail Panel, a new entry is added under "Toolbar setup" called "Opera Standard (modified)". I have now several, including one called "Opera Standard" which, when I select it, simply closes the entire panel (and as soon as I open it, a new entry is made as "Opera Standard (modified)". What the heck is going on???

If you open/close the panels, that counts as changing the state of a toolbar.