Tar options in hdup?

After I had it working for a while (so I thought) I am once again
getting all my mysqlhotcopy'd databases backed up every day. So the
problem I thought I had solved by hacking tar seems to have
reappeared. Can't figure it out.

For history here's my original thread:
http://article.gmane.org/gmane.comp.sysutils.backup.hdup.general/109/match=mysqlhotcopy

But the upshot is that tar appears to consider a current "ctime" as a
reason to back something up even though the modification (mtime) is
not recent. Since I use mysqlhotcopy to back up mysql databases before
hdup archives them, they always have a current ctime even though the
mtime may be unchanged for some tables that really have not changed.

Anyway I had basically removed all code comparing ctime from the tar
source and recompiled. It seemed to work for a while and suddenly my
backups started getting huge again.

I am wondering: What options does hdup invoke tar with as of the
current version? Did this possibly change at any point in the last 4
months?

-- Jamie