modifying iceweasel settings

I wanted to modify iceweasel so that it would not display ads.
I found information on using
userContent.css files for this at
http://www.floppymoose.com/
and dropped the file into
.mozilla/firefox/lotsoflettersnumbers.default/chrome/
where lotsoflettersnumbers is some random string you can find on your machine.

then i modified a setting or two and it worked fine.

on another machine, though, it did not work.

there were two directories .mozilla and .mozilla.org

so i tried

.mozilla/firefox/lostoflettersmumer.default/ and i created a chrome directory and dropped it in
no go
i also dropped it in
.mozilla/firefox/lostoflettersmumer.default/ itself but no go.

i also tried to drop it in
.mozilla.org/firefox/xxx.default/chrome
and
.mozilla.org/iceweasel/firefox/xxxx.default/chrome

as well as dropping it in
/etc/iceweasel/profile/chrome
so on that machine, i am stuck...

i tried a new user on that machine. it worked, she only had a .mozilla/firefox/xxx.default/chrome directory so it worked fine there.

so i just blew away my .mozilla directory (.mozilla.org.org) then started again and it created
the correct tree including a chrome directory and then i copied in the userContent.css file and i was done.