This is just my astronomically humble opinion, but I think most chipped ps 2's have this "problem" with booting from the browser.
Mine does this too, and it's brand new (although mine has a Magic 2 no-swap; don't know about Messiah). I have to put the game in, and reset to get the game to boot. The shop owner told me this was to be expected from a chipped machine.
That's my two cents; hope it helps
