7.2 upgrade

hi all,

i'm pretty new to postgres, and thus the post to novice.

i tried to perform an upgrade to 7.2 today and have run into some
problems at the very end of the process.

after making 2 pg_dumpalls (one for globals and one for the data),
stopping postgresql, installing the appropriate 7.2 rpms, and then
starting postgresql again, i tried to put the data dumps back in and had
an error thrown back at me.

here's what i did pre install:
sudo -u postgres pg_dumpall -g -h myDB > /u/tchatter/globals_dbdump.txt

sudo -u postgres pg_dumpall -o -h myDB > /u/tchatter/all_dbdump.txt

post install:
sudo -u postgres /usr/bin/psql -d template1 -f
/u/tchatter/globals_dbdump.txt
sudo -u postgres /usr/bin/psql -d template1 -f
/u/tchatter/all_dbdump.txt

at which point i got:
psql:/u/tchatter/all_dbdump.txt:323: \connect: FATAL 1:  IDENT
authentication failed for user "karl"

so i figured that something was wrong with the pg_hba.conf file
but i'm not quite sure what i'm looking for in order to correct it.

i'd appreciate any pointers for where to look next.
thanks!
tuna