It looks increasingly likely that the release candidate for Firefox 4 will not be released in February the month many believed the browser would be launched.
Instead, a March release looks more probable, with at least one more beta due and a 13th a possibility as well.
The 12th beta, still planned to be the last, has not been released yet, with just six days left until the end of the month.
Firefox release manager Christian Legnitto recently explained on the Mozilla developer site the browser maker reserved the right to issue a 13th beta if there were more issues to resolve.
A tweet from Mozilla's Asa Dotzler has given Firefox fans reason to hope for a release soon, but still no specific date has been given.
"From what I can tell, there are only seven unwritten patches standing between Firefox 4 and hundreds of millions of users," Dotzler said.
Firefox 4 has been plagued by delays as Mozilla developers have sought to ensure the release candidate contains no bugs whatsoever.
One recent note from a Firefox planning meeting said the 12th beta had "a small enough list of bugs that it's plausible it will be the last beta, though we're not locking that up, since some of the plugin work needs to crystallise before we can assess timing risk."
It's been a fairly turbulent couple of months at Mozilla, with the release of the 10th beta appearing towards the end of January.
Then there was the announcement at the start of February the 11th and 12th beta versions of the browser would be released.
Earlier this month, it emerged Mike Beltzner, director of Firefox, would be leaving the company after his work on the latest browser was completed.
In that same week, a Mozilla developer courted controversy when criticising Microsoft's Internet Explorer 9 for not being a modern browser.
