UTF-8 data migration problem in Postgresql 7.2

Dear all,

I tried to migrate a UTF-8 database with Japanese content from Postgresql 
7.1.3 to Postgresql 7.2 unsucessfully.

I made a pg_dump of the 7.1.3 database and tried to upload it in 7.2.
Error message was "Invalid Unicode character sequence found".

I tried to upload data in a fresh PostgreSQL 7.1.3 database and everything 
worked OK. The problem can be reproduced on PostgreSQL 7.2.

Do not hesitate to ask me for a pg_dump of the involved tables. I cannot 
submit them on the list for privacy reasons. Thanks for your help.

Cheers,
Jean-Michel POURE