Mari0,
Make sure you have version 1.7 installed. You can tell by the about screen having an orange background (uhm, and by not crashing on 38xx devices).
I've played through all of the missions with 1.7 without a single problem on my 3870 device.
Reports indicating that the problem is still there turned out to be messed up installations (e.g. no uninstallation before installing 1.7) or doing something wrong.
I've received lots of report from people indicating that 1.7 works fine on their 38xx devices.
(Also make sure you have all the updates and fixes from Compaq installed. 38xx still has lots of bugs in it (like random memory corruption during activesync, etc), but Snails 1.7 should work on it)
Additional info: Now it works for Hamish, after reinstalling 1.7 it correctly (after uninstall on PocketPC AND Desktop and installing 1.7 only after that)
