The position is this. Inform 5.5 is _not_ officially out at the
moment and you use it at your own risk! The source I posted (but
didn't announce) was just to let people like Bob kick it around
for a while before a proper release.
Several bugs have been found and fixed already. To avoid this one,
compile everything with an explicit commandline switch as -v3 or -v5
according to taste.
Or wait for the official version! It won't be long. And it is much
better than 5.4.
Graham Nelson
PS: The 5/10 libraries are more or less required for using 5.5, but
they're also experimental at the moment.