Characters from embedded Google fonts not showing up in Firefox 4 and IE9

Posting here is a bit of a long shot (I can´t reach the developer), but I´m having a problem with a font that I´m embedding using Google web fonts.

The font I´m embedding is Molengo and the problem I have is that the capital Z does not show up in Firefox 4 nor in IE 9. It does show in Chrome 10.

In Firefox 4 the character occupies space and in IE9 it is totally collapsed.

I can reproduce the problem not only on my test site, but also on the official Google web fonts page. At least on my computer the box of the Z does not show the character in Fx4 and IE9 and I don´t have another machine at hand to test on.

Clicking around on Google web fonts, I found the problem at other places as well, like the % character of the Candal font family.

So is my computer just going crazy or is there a problem with random characters from Google web fonts in Fx4 and IE9? And if it is the latter, is there a solution for this problem?

Edit: I just tried generating some Z's using Molengo on Font Squirrel, but they only seem to generate images instead of actual texts.

I have downloaded the same font from Font Squirrel, uploaded it to my own server and included all types like in the demo page and now it shows the Z both in Firefox 4 and IE9.

And all other characters as far as I can tell :-)

Very weird, the problem seems to be related to Google web fonts only.