Are you certain this is the same bug?
Control: merge -1 818971
818971 discusses general compatibility issues and talks about other crashes.
This one specifically concerns the bad_alloc crash, which isn't mentioned in
818971, as far as I can tell.
I'm suggesting an un-merge.
Also, upstream reports the extension as being compatible:
"Works with Firefox 13.0 and later, Thunderbird 13.0 and later"
They also mention a possible workaround:
"If you experience SEGFAULTs, it may be due to a bug in Mozilla's new JIT
compiler. Try disabling it by setting javascript.options.baselinejit.* in
about:config to false."
I haven't tried it yet, however.
Addon page on mozilla.org:
https://addons.mozilla.org/en-US/firefox/addon/kde-wallet-password-integratio/
