[Freeciv-Dev] (PR#11980) freeciv 2.0.0.beta6: disappearing units

["dssr@xxxxxxx" <dssr@xxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=11980 >

system: debian linux kernel 2.6.9-nitro4 patched, libc 2.3.2ds1, libglib
2.6.4
freeciv 2.0.0beta6, german, locale iso8859-15

i placed a catapult unit on an island, after a few rounds it
disappeared, in the city which owns the unit, a field still exists but
without the corresponding icon (see attachment)
a similar thing happened with an explorer, it seems to be there, but
cannot be seen. 
i toggled some views a few times (units, cities) before i recognized
this issue, but couldn't notice a direct connection with it, i just
write it because perhaps it has to do something with it.