I have the following in my .vimrc

:no ø l
:no l k
:no k j
:no j h

(This to move the movement keys to the right to accomodate touch "rules" on Norwegian keyboards.)

In the 2.4/2.5 series this worked, but at some point in 2.6 the first mapping, the one with 'ø', started to fail (I'm not sure exactly when, but probably not before 2.6.2, upgraded a lot, both system and Qt in this period.)

This failed by doing nothing.

I have downloaded and compiled the 2.7 branch, but there pressing 'ø' cause a crash when it tries to "clear bad mapping" and goes out of range.

The last from the log
KEYPRESS 0 "?" 'HANDLE INPUT: 0 - 0 - "?"
ASSERT failure in QVector<T>::remove: "index out of range", file ../../../../../../Qt5.0.1/5.0.1/gcc_64/include/QtCore/qvector.h, line 368

My suspicion (because this used to be a problem early on) is that non-ascii characters in the mapping are messed up, either at the time of reading the .vimrc, and/or when processing the key.