PostgreSQL 7.4.7-6sarge3 to bpo postgresql-8.1

[lbmlist@hethcote.com]

Is this possible with an existing 7.4.x database?

Selecting previously deselected package postgresql-8.1.
dpkg: regarding .../postgresql-8.1_8.1.4-6~bpo.1_i386.deb containing 
postgresql-8.1:
 postgresql-8.1 conflicts with postgresql (<< 7.5)
  postgresql (version 7.4.7-6sarge3) is installed.
dpkg: error processing 
/home/lbmoore/downloads/postgresql-8.1_8.1.4-6~bpo.1_i386.deb (--install):
 conflicting packages - not installing postgresql-8.1


It sort of looks like the pg_dump from postgresql (<< 7.5) might not be 
readable in 8.1


Louis