1. everything looks like a perfectly normal backtrace except for the crash.

2. same image, same VM started with UI (non-headless) works just fine, no crash at all

ref:

Pharo image: core

Pharo core version: Pharo1.3 update #13298

Virtual machine used: Squeak-4.4.7.2357-linux_i386

Class browser used if applicable: OBSystemBrowserAdaptor