I found some freeze/hang/crash points in xu4, all in the dungeons. I'd imagine y'all may have seen some of these already, but if not, here's what I found in my most recent playthrough. This was with the U4 Upgrade package installed as well.
General: getting chests seems to be bugged, at least in some dungeons, like the Abyss
Shame: climbing the ladder from level 8 to level 7, turn right, and the game freezes/hangs;
note: music continues to play, but xu4 ceases to respond; computer fan also revs up quite a bit;
fan calms down after force-quitting and restarting xu4.
Only restarting xu4 and using the Y-up spell works; must use Z-down on the way back to the altar
room.
Despise: upon climbing the ladder from level 6 to level 5 (the one that's NOT with the many
treasure chests!), again requiring the use of Y-up and Z-down due to hanging/freezing as
described above. Note that this dungeon also hangs the same way upon peering at a gem, and even
with using the cheat menu (Ctrl-c, then p)! That problem may also occur anywhere in other
dungeons, IIRC.
Wrong: within THE ENTIRE DUNGEON(!), if you ignite a torch or cast Light, the game freezes/hangs
as described above. This is a bug that may occur in some dungeons, but not others. As a result
the player is forced to consult the web for a map to use, since Gems/View may also not work here
Deceit: taking the west exit out of the southeast room on level 7 freezes/hangs the game as
described above. Interestingly, you can successfully take the south exit out of the northwest
room on the same level, but DO NOT turn right to face the wall, or the game hangs as described.
Abyss: at the final altar when you get asked a bunch of questions about the virtues, the "is xu4
installed?" error pops up, and the program crashes. Cannot get past this, though I could probably use the savegame in vanilla U4 to finish. Edit: huh, just tried that, but vanilla U4
isn't seeing it somehow, just starts up some other existing save, despite the fact that I don't
seem to have one at all in the vanilla U4 directory. Very odd.
Hmm, I think I actually beat the game successfully in xu4 WITHOUT the u4upgrade patch. Could be worth looking into. Anyway, these are the bugs in xu4 that I could find, so if anyone's still working on this, I'd GREATLY appreciate it if y'all could fix 'em! Thanks!
Urk, forgot to mention this was on Win 7 using DOSBox 0.74. If y'all need more info, just let me know!