copy DB data from FreeBSD to Redhat9.0

[sam wun]

Hi,

I just fresh install mysql4.1 in Redhat9.0.
I have another MySQL5.0 installed in FreeBSD5.3, and just tried to copy 
all data in /var/db/mysql/ from FreeBSD5.3 to /var/db/mysql/data/ in 
Redhat9.0.
After finished copied the data over to Redhat, MySQL4.1 can't start. The 
DB data in MySQL5.0 in the FreeBSD box has database and tables with indexes.
I don't want to rebuild the entire database from scratch in Redhat, how 
can I "transfer" all db files from FreeBSD to Redhat and in another 
version of MySQL?

Thanks
Sam