I tried "franz craps" ( http://csdb.dk/release/?id=117421 ) with REU enabled, and it crashed scpu64 with a segfault.
Used linux (debian), and nightly build (from today, 4.6.2013)
tried also x64+REU, and it works.
(the REU is only used to clear/color the screen. at init, the demo fills one page with 00..FF, and later it uses this to erase a screen, keeping REU-address constant)