I would like to migrate from Release 3.1.4_GA_518.FC3_20060626143230 FC3 FOSS edition on an older fc3 server to
Release 4.5.6_GA_1044.RHEL4_20070706161941 CentOS5{i} NETWORK edition
on the new server running redhat enterprise 5 (CENTOS)

I have read a bunch of forums here and even a reply to a post from me that states i should stop zimbra on the old server backup the /opt/zimbra dir and copy it to the new server. Then install the old version (Release 3.1.4_GA_518.FC3_20060626143230 FC3 FOSS edition) to the new server overtop of the copied /opt/zimbra. Then upgrade to the latest version for redhat 5.

Will this work correctly considering different os version are being used? is the 3 to 4 upgrade successfully?