In order to analyze this further I need to know if you're running on PowerPC or Intel. The build number in your crash log for 10.4.6 doesn't match mine (PowerPC), so am I right in assuming you're on Intel?
This one is potentially fixed by the changes that were made in order to fix bug #388 and bug #397. I suspect that the same underlying cause may have been at the root of it all. Will monitor this bug closely and see if is reproducible when the next version comes out (the version containing the fix for the aforementioned bugs).
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