VM builders:
Recent updates in Squeak trunk expose an issue with the FloatMathPlugin. This plugin should be built with compiler optimization turned off, otherwise the plugin can crash the VM.
The Mantis report is at http://bugs.squeak.org/view.php?id=7592 and the discussion on squeak-dev is at http://lists.squeakfoundation.org/pipermail/squeak-dev/2010-December/156132....
Although this has not been verified on all platforms, the working assumption should be that optimization must be turned off for FloatMathPlugin when using gcc.
Dave