If your typing out your content in another language then there may be some characters that are not displaying properly with Cufon.
When this happens you can do either of these three workarounds.
Navigate to Dashboard -> your theme -> General Settings and there will be an option there where you can easily disable Cufon on your site. http://mysitemyway.com/docs/index.php?title=General_Settings#Cufon
When Cufon is disabled all characters will be displayed but the Cufon font will not be used. This is probably the best option for languages with large amount of symbols such as Chinese or Japanese due to performance issues.
Reconvert the font files
Depending on your language you can also choose to reconvert the font file and include your characters so they display.
1. You'll need to figure out which font that you want to use first. You can view the current fonts being used in the skin editor, http://mysitemyway.com/docs/index.php?title=Creating_a_new_Skin#General_Typography.
2. Next you'll need to convert the font file to Cufon by following the steps on this page, http://cufon.shoqolate.com/generate/. Just make sure to check the glyphs that you'll need. If you have accented characters for example then you'll probably want to check the "Latin-1 Supplement" glyphs.
3. When your done converting your font file you should receive a YOUR_FONT_400.js file or something similar.
You'll need to rename this file to something simple such as "verahumana.js" and then open up the file and you should see a line like this,
Rename the font name to whatever you named the file as like so,
For example if my file was called "Rapscallion_400.font.js". I would rename the file to "rapscallion.js" and inside the file I would changed it so the name matches the filename,
4. After your done renaming and editing the .js file you'll need to upload it into /wp-content/themes/[your_theme]/lib/scripts/fonts/ and it should now display in your skin editor for you to use.
WP Google Fonts
Probably a much easier solution is to use the WP Google Fonts plugin, http://wordpress.org/extend/plugins/wp-google-fonts/.
It uses the CSS @font-face rule so it's a bit faster than Cufon and it also allows the user to select the text so it would be a better choice if used on a body font.