enable_availability_zones(), disable_availability_zones() bug

[GoogleCodeExporter]

What steps will reproduce the problem?
1. create a ELB with two zone: us-east-1b, us-east-1c
2. call disable_availability_zones() to disable us-east-1c
3. call enable_availability_zones() to enable us-east-1b

What is the expected output? What do you see instead?
for disable, the return should be us-east-1b
for enable, the return should be us-east-1b, us-east-1c
however, both calls return a empty list []

What version of the product are you using? On what operating system?
2.0, centos5.5

Please provide any additional information below.
AWS returns the expected result, however when get_list() seems fail to parse 
the xml string correctly.

Original issue reported on code.google.com by jass.z...@gmail.com on 28 Jul 2011 at 10:37

[GoogleCodeExporter]

Is there any chance you have the actual XML response data returned by AWS for 
these requests?  The AWS documentation is annoyingly incomplete in this regard 
and trying to reproduce this is time-consuming.  It should be easy to fix if I 
can just see the actual output.

Original comment by Mitch.Ga...@gmail.com on 25 Oct 2011 at 7:52