EXACT STEPS LEADING TO PROBLEM: 
1. open this bug report in your web browser
2. click on the url for this bug report
3. open the browser menu and selection options, adjust view, text size, the
middle one (enus:Large, enus1:Medium)
4. scroll to the bottom and look at the box labeled "Bookmarklets"

EXPECTED OUTCOME:
➡ ➨ ➯ ➔ ➞
➽ ➹ ✩ ✿ ❥ ›
⌘ ‽ ☁ ta.gd  

That's:
a row with: five arrows,
a row with: two arrows, a star, a flower, a sideways heart, roughly a greater
than "›"
a row with: apple's command flower, an exclamabang (?!), a cloud, "ta.gd"

ACTUAL OUTCOME:
a row with: five ='s (it's a replacement character)
a row with: five ='s (it's a replacement character), roughly a greater than "›"
a row with: three ='s (it's a replacement character), "ta.gd"

REPRODUCIBILITY:
always (but only with the n900, it works fine on Windows XP/7 with Firefox, or
OS X 10.5.8 with Firefox or Ubuntu 9.04 with Firefox).

EXTRA SOFTWARE INSTALLED:
Droid Fonts (also happens without them)

OTHER COMMENTS:
This is a problem because IDN url shorteners are becoming popular and it
results in a rather poor user experience. Note that the results are slightly
different if one taps into the drop down in this web page (you get boxes with
the unicode codepoints), but not better (and we don't intend to change this
behavior, although it would be automatically fixed if someone provided fonts
for this).