I checked some files.
It looks like there's no big change with maian 1.5.5 except the installation routines that are different with jml1.5. (that's big allready) (i changed the component 1.5.5 myself and installed it in jml2.5 and had also the same issues).
So my guess is that the 1.5.6 is not yet optimized for working with jml2.5, but Alao said he was working on it.
So have to be patient.