Description of problem:
enable the scalable app auto scaling, trigger the auto scale up function, will get error message, and scale-up cannot be successful.

Version-Release number of selected component (if applicable):
stage-2.0.8

How reproducible:
always

Steps to Reproduce:
1.create scalable app
2.ssh login to the app and start the auto scaling
haproxy_ctld --debug &
3.do some parallel connections and trigger the auto scale up
4.check the scale_events.log
tailf <gear_name>/logs/scale_events.log
  
Actual results:
Auto scale up got failed 

Expected results:
auto scale up should not get any problem and the gears count should be increased.

Additional info:
I, [2012-03-31T06:47:57.872265 #26325]  INFO -- : GEAR_UP - capacity: 390.0% gear_count: 1 sessions: 39 up_thresh: 90.0%
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require': no such file to load -- rest-client (LoadError)
	from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
	from /usr/libexec/stickshift/cartridges/embedded/haproxy-1.4/info/bin/add-gear:4


Cannot reproduce this issue on devenv-stage_155