It has been reproducing, after aviary branch is made. When new build is started for the first time, an application icon appears several times and disappears. Once an icon appears in doc, as for start from the 2nd time, it will not disappear. This is the same operation as the case where Finder crashed, and it was automatic and reboots. This is bad also on user experience. (For the user using Firefox, it is bad together with bug251613 for the first time.) And this problem is also reproduced by thunderbird. Mac OS X 10.3.5

Could this be because of the several calls to nsAppRunner:LaunchChild that is done? Especially if importing profiles or other 'one time' tasks are run?

That's exactly what's going on, see bug 271613.

Because of this problem the newly launched application is not the foreground app after launch. It does have the front-most window, though. nit: Can someone correct the spelling of "Dock" in the summary?

Fixed in bug 345057.

I tried tinderbox-builds. But it still reproduces... Mac OS X 10.3.9 Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.9a1) Gecko/20060720 Minefield/3.0a1

The fix is effective for me on 10.3.9. Be sure you pulled your source after bug 345057 was checked in. There is no official 0720 nightly in firefox/releases yet, but whatever you find in firefox/tinderbox-builds/bm-xserve02-trunk should have the fix. Note that when the application decides to restart itself, the Dock icon may still not stay entirely static. There's nothing we can do about this, because we are exiting one process and starting a new one. The goal of the dock icon fix in bug 345057 was to make sure that the dock icon doesn't disappear for extended periods of time. Any disappearing and bouncing that you see now is the least erratic form possible, and we can't do any better without getting rid of the restart/exit (bug 271613). If you compare the first launch of the 0720 official build (when it's out) to the 0719 official and can see that the dock icon or triangle shows up sooner after relaunch with 0720 than with 0719, then the fix is effective.