Update from Nova Media
With a little help from Nova Media (who were very prompt in responding), I managed to get launch2net and Parallels 3.0 to play nice together. Here are the instructions as received from Nova Media:
We have discovered that problems with the upgrade from 2.2 to 3.0 in
Parallels can leave something behind that produces incompatibility not
only with Launch2Net but with VMWare and Cisco. The new version does not
uninstall or trash any unneeded file from previous version.
The solution is to uninstall Parallels completely (following the
instructions in
http://forum.parallels.com/thread11880.html), launch
Launch2Net and configure it, save the configuration and connect to
introduce the software activation code. Thereafter, Parallels 3.0 can be
installed anew and keeps the activated status and the last loaded VM.
Now, both return to cohabitate peacefully.
Let me emphasize (since I overlooked it myself) that you MUST actually CONFIGURE and ACTIVATE launch2net BEFORE installing Parallels 3.0. If you just install launch2net without configuring it, then install Parallels, launch2net will fail to launch the next time.
--Dan