Issue #3523 has been updated by B Kelly. File test_em_fiber4f.rb added Hi, I've attached a program (in redmine) which reproduces the c0000029 crash on ruby_1_9_2 / Windows 7. The program is a single source file, but it does depend on the EventMachine extension. The crash happens every time for me. There are comments at the top of the source file explaining how EventMachine was built, and describing lines which can be added or removed to alter or prevent the c0000029 from occurring. I'm using Visual Studio 2010 to compile both ruby and EventMachine. If there's any way I can help please let me know. Thanks, Bill ---------------------------------------- http://redmine.ruby-lang.org/issues/show/3523 ---------------------------------------- http://redmine.ruby-lang.org