Proguard doesn't work, need more guidance in licensing docs

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Followed the licensing guide
2. Tried to use proguard to obfuscate
3. Application force closes

I've tried every site that I could find that mentions android and proguard, and 
explicitly excluding my classes with Keep public class but app still force 
closes.

This needs to be much easier.  I have apps to publish that use the licensing 
server but I can't safely without obfuscating and it seems nearly impossible. 
So presently stuck. Wish simple eclipse plugin did this using the safest 
possible proguard options so it would always work.

I followed guidance here but still get force close:
http://android-developers.blogspot.com/2010/09/proguard-android-and-licensing-se
rver.html

What is the expected output? What do you see instead?

What version of the product are you using? On what operating system?
Latest android sdk, running on droid x with 2.2.  App runs fine without 
proguard on emulator and droid x.  No options to proguard seem to help.

Please provide any additional information below.

Original issue reported on code.google.com by DavesA...@gmail.com on 2 Oct 2010 at 4:58

[GoogleCodeExporter]

Close this issue.  The issue turned out to be corruption in the class files.  
This seems like it can happen if working with eclipse to build and command line 
builds.  Just delete all the class generated files and rebuild from the command 
line and everything works.

Original comment by DavesA...@gmail.com on 4 Oct 2010 at 12:28