Upgrading from 6.3.2 to 7.0.2

I've got a database I would like to upgrade from 6.3.2+phpfi 2.0 to
7.0.2+php 4.0. I've found the changes needed to be made to the php code,
and that should not be a problem. The real issue I'm having at this point
is getting the data into 7.0.2, or any newer release of PostgreSQL. I've
tried the pg_upgrade, but it does not seem to work for 6.3.2 -> 6.5.3.
Should I try 6.4 first, then 6.5.3, then 7.0? I've tried pg_dump and
pg_dumpall, but the data will not insert into the newer version
database. Do I need to provide some err info here? What would be helpful?

Notes on this setup: I've inherited the DBA position for this database. I
know the people who designed and built it, but cannot get any help from
them. They added some special charactor types and some compiled C code to
the postgres install, and I think that may be what's throwing the process
out. Any suggestions?

Thank you,

Chris Sterling
lemmy(at)eaze(dot)net