Odd message with initdb on latest HEAD

I run initdb and get:

LOG: database system was shut down at 2005-06-29 11:57:10 WST
LOG: checkpoint record is at 0/353E68
LOG: redo record is at 0/353E68; undo record is at 0/0; shutdown TRUE
LOG: next transaction ID: 548; next OID: 10792
LOG: next MultiXactId: 1; next MultiXactOffset: 0
LOG: database system is ready
LOG: transaction ID wrap limit is 2147484132, limited by database
"postgres"
LOG: checkpoints are occurring too frequently (1 seconds apart)
HINT: Consider increasing the configuration parameter
"checkpoint_segments".
LOG: transaction ID wrap limit is 2147484132, limited by database
"postgres"

What's going on in initdb now that we are checkpointing too quickly?

Chris