bzr dpush and large network transfers with multiple commits

[Gary Wilson Jr.]

If I dpush after having made a single commit, all seems fine and
network traffic is small.  However, if I perform more than one commit
in my local branch and then attempt to dpush, I consistently see
extremely large amounts of data transferred even for very small
changes.  For example, I just tried dpush'ing two commits of about 10
lines total and ended up with 318MB transfered.  Here's the tail end
of that log:

86.681  Packing repository
GCRepositoryPackCollection(CHKInventoryRepository('file:///project/.bzr/repository/')),
which has 8 pack files, containing 917 revisions with hint
['6fefc1f1029f3c452059c8b1552099f0'].
86.682  repacking 2 revisions
86.683  repacking 2 inventories
86.685  repacking chk: 2 id_to_entry roots, 1 p_id_map roots, 4 total keys
86.692  repacking 2 texts
86.696  repacking 0 signatures
[ 7595] 2010-04-30 11:16:25.968 INFO: Pushed up to revision 764.
87.344  Transferred: 317853KiB (3702.9K/s r:0K w:0K u:317853K)
87.344  return code 0

bzr plugins reports that I'm using svn 1.0.2dev.  Any ideas as to
what's going on here?

Gary