Not about SDL, but still worth mentioning. Both on 0.7.0 and 0.7.6/7.
XFree86-DGA is reportedly disabled by default (at least when using xorgconfig or similar). Looks like this:
SubSection "extmod"
Option "omit xfree86-dga" # don't initialise the DGA extension
EndSubSection
However, if DGA is enabled, mouse
may be delayed or lagging on high load, including menus. (This was from running OA with a nice'd bzip2 in the background, on an old Pentium III (yay) -- not sure if this applies on a
real computer, hence the "may.")
(Apparently trying to run Open Quartz on
glxquake, which needed DGA enabled.)