Found this problem in exult and found out that is common to all SDL 1.2 apps. In fullscreen the movement is borked:
https://answers.launchpad.net/ubuntu/+source/ … question/200823

Marzo proposed a solution here:
http://log.usecode.org/exultlog.php?log=9Dec2012

It works. Ignore my flaying around with SDL, i fixed that problem and compiled and saw it fixed.

edit:: here is marzo's commit: http://bazaar.launchpad.net/~exult-team/exult … n/revision/6035