In all version fo Jigsaw, there has been a limit of the size of the files
you were able to serve, in the 2GB range, because the size was an int
instead of a long.
You can look in  for the new classes (source code is in CVS). It should
upgrade nicely from the 2.2 series (It's in place in two production
servers), so everything should be transparent. If you made extensions
using content-length, there will be a warning at compilation time about
possible loss of precision.