warning: dereferencing type-punned pointer will break strict-aliasing rules

[Jeffrey Holle <jeffreyholle@xxxxxxxxxxxxx>]

I am using gcc version 4.1.2.

I am writing a Boost.Build based system to build wxWidgets using 
applications.

This build system has default build variants "debug" and "release".

On release builds, wxWidgets code emits a lot of these warnings:
  warning: dereferencing type-punned pointer will break strict-aliasing 
rules

Questions:

  1.  Are these warnings benign?  If so can they be suppressed?
  2.  If not, what level of optimization should I regress to avoid these
warnings?