It may very well be that K-Meleon is vulnerable to
more or less secure. Using NoScript may help also,
but this is not yet ascertained.
Some details here :
If you have whitelist containing only a few sites
that you believe to be trustworthy (or better, that
you think are watched closely and frequently by the
responsable webmaster), and give permissions to no
other site, you should be rather safe, but if you allow
it depends on the anti-clickjacking power of NoScript,
which I cannot yet judge, how safe you are.
As Guenter said, it is advisable to clean cache and
history, close down and restart the browser before
doing an important action.
There may still be the possibility, that a bank site
has been changed, but then you could hold them
responsible for your damages.