I use only the regular HTTP addy, but have on rare occasions seen more or less the same here in Firefox ... usually, but not always, a page reload clears it up, particularly if I clear the cache first.
One other possibility occurred to me, at least in my own case ... my graphics controller is an antique Intel 82845-series onboard chipset, for which updated drivers haven't been available in ages, and it has problems with one game in which it'll occasionally lock up and eventually give me an error message that a DLL driver for it failed to operate, and the whole system then drops back to 4-bit 640x480. Everything's good as new if I reboot ... I've never run into that problem in any other context, so I assume the game's trying to call a function that the controller never heard of and there's nothing wrong with the controller itself (or its drivers), and probably totally unrelated to the forum display thing some of us are occasionally seeing.