Application state isn't always saved

I've been using r27 mako for three days now, and very often when I switch applications they are restarted.
Examples: I was using gmail webapp and browser, gmail to get an information and browser to do some research, when I switched from webapp to browser and back to the webapp, it made me login into gmail again, as if I just had opened it. I logged in again, went to browser, and returned, same happened, I was asked to login again. At this time I had only these two applications open plus Facebook webapp.

Yesterday while playing Solitaire the screen locked, and when unlocked it the application went to initial screen, like if I had just opened it (it reset my freecell game, bummer!). I could reproduce that several times, by locking and unlocking the screen or switching to other screens (going to Home and returning to game, for example). I had three apps opened the first time it occurred with Solitaire, I then closed them and let only the game open, and the problem still persisted.

From IRC:

<ogra_> Ursinha, yeah, thats by design
<ogra_> and not a new issue
<Ursinha> ogra_, resetting my game is a really bad design decision :)
<ogra_> it definitely is
<ogra_> usually apps in the bg store their state since they are only SIGSTOPed ... but if you have enough of them open they are actually killed in the bg and restarted when you switch to them
<Ursinha> ogra_, the solitaire was the only one opened
<Ursinha> I closed everything else thinking it could be lack of resources like you said
<ogra_> i see it with about 5-6 webapps open usually