After some time using conkeror, URL completion stops working. However, completion for M-x still works.
Not sure how to reproduce this yet.

After some point, as I type a URL, the following error message gets printed:

Error: 
chrome://conkeror/content/utils.js:338
abort()@chrome://conkeror/content/utils.js:338
(true,true)@chrome://conkeror/content/minibuffer-read.js:273
(0)@chrome://conkeror/content/minibuffer-read.js:234

Trying to autocomplete (TAB) prints this error message to the console:

Error: 
chrome://conkeror/content/utils.js:338
abort()@chrome://conkeror/content/utils.js:338
(false,true)@chrome://conkeror/content/minibuffer-read.js:273
minibuffer_complete([object Proxy],1)@chrome://conkeror/content/minibuffer-read.js:372
([object Object])@chrome://conkeror/content/minibuffer-read.js:415
call_interactively([object Object],"minibuffer-complete")@chrome://conkeror/content/interactive.js:143
_do_call([object Generator])@chrome://conkeror/content/coroutine.js:279
co_call([object Generator])@chrome://conkeror/content/coroutine.js:427
input_handle_keypress([object KeyboardEvent])@chrome://conkeror/content/input.js:304

Version: conkeror.mozdev.org conkeror 1.0pre

A new error message which comes up some times:

Error: 
chrome://conkeror/content/utils.js:338
abort()@chrome://conkeror/content/utils.js:338
()@chrome://conkeror/content/minibuffer-read.js:205
()@chrome://conkeror/content/minibuffer.js:266
exit_minibuffer([object Proxy])@chrome://conkeror/content/minibuffer-read.js:456
([object Object])@chrome://conkeror/content/minibuffer-read.js:465
call_interactively([object Object],"exit-minibuffer")@chrome://conkeror/content/interactive.js:143
_do_call([object Generator])@chrome://conkeror/content/coroutine.js:279
co_call([object Generator])@chrome://conkeror/content/coroutine.js:427
input_handle_keypress([object KeyboardEvent])@chrome://conkeror/content/input.js:304

Yeah I'm finding this impossible to isolate as well (though it certainly happens often enough).  After
running Conkeror exclusively in safe-mode for a few days, though, I'm somewhat confident that the bug is
avoidable that way.

On the other hand, the only extension I have is AdBlock Plus, and the bug DOES persist if I disable that
in the extensions menu and run Conkeror normally.

Version:
conkeror.mozdev.org conkeror 0.9.4 (Debian-0.9.4-1)

The -safe-mode flag definitely does neutralize the bug, for some reason.

This isn't an rc issue or anything, bug shows up on a freshly installed and completely vanilla Conkeror.

Possibly irrelevant details about my system:

Debian Testing (Wheezy)
Mozilla XULRunner 8.0 - 20111109093931
xorg 1:7.6+9
xmonad 0.9.2

Since upgrading to xulrunner 9, this bug doesn't seem to come up any more.