Changelog:
envy (0.4.2-1ubuntu10) unstable; urgency=low
* Changed: if the driver can’t be downloaded from the ftp address envy will get it from the http mirror
– Alberto Milone (tseliot) <albertomilone@alice.it> Wed, 20 Sep 2006 10:07:43 +0200

As you can see from the changelog you shouldn’t have problems with the download of the driver as if the transfer via ftp fails Envy will get the driver from the http address.

Enjoy!