I do know that there are problems with libstdc++.so5 and libstdc++.so6 being incompatible but shouldn't the deb file make sure that the correct file exists?
Sarge users would have to backport the engine due to the libc6 dependency that dpkg checks at install.
#
libc6 (>= 2.3.5-1) [not i386, ia64]
GNU C Library: Shared libraries
libc6 (>= 2.3.6-6) [i386]
#
[dep] libc6.1 (>= 2.3.5-1) [ia64]
GNU C Library: Shared libraries
Granted Etch will soon be released... I'm thinking on the day before Duke Nukem Forever hits the stores ;-p