I have converted the updated planet file to osm.xml with

osmconvert planet.osm.pbf --emulate-osmosis > planet_osmconvert.osm

and

osmosis --read-pbf file=planet.osm.pbf --write-pbf file=planet_osmosis.osm

I did not write the whole file and compared the first million lines.

The first relevant diff is:
osmconvert:


osmosis:

The difference of the longitude (osmosis - osmconvert) in all differences I checked is a constant number: 429.4967296

Does that help?

WanMil