yslow needs firebug for run properly and i found out that if you
upgrade your firefox to last version (9.1) firebug will be upgrade to
(1.9) and so yslow will not work anymore
https://addons.mozilla.org/en-US/firefox/addon/yslow/versions/
i suggest this versions :
firefox : 7.0.1 (and disable automatic update)
firebug : 1.8.2
yslow : 3.0.4
and these are really compatible with each other :)
When I test in Windows Vista using Firefox 9.0.1 and Firebug 1.9.1, all 5 lines you mentioned print as expected.
But the problem remains on my linux machine, running Ubuntu 10.04.