use getBytes("UTF-8"); instead of getBytes();

_createVCardFromXml in org.jivesoftware.smackx.provider.VCardProvider seems to have a bug, depending on the local charset.
It may be much more safe to use UTF-8 to encode the supplied string.

There are some other lines of code where getBytes() is used, they may also cause trouble.

The Wildfire code should also be reviewed for similar lines of code.