User-agent: K-Meleon/1.6.b2.4
This bug happens in 1.5.x and above.
It happens when you type a character that has too much references in a cross check to the full history.
So, with that behavior, when you type a character, or, better said, an string, that matches lots of entries, there is a memory overflow and crashes.
For example, when you write
www.whatever.com. When you type www., comes the memory overflow (loads of matches for www., what is normal, by the way) and crash. No time for crashreport plugin to catch the error.
Bug 1358 - Url bar autocomplete feature crashes browser when comparing matches