In
some cases, after installing SP1 or hotfixes for WSS or MOSS, the
version number reported in the site settings remains at the same version
as before the upgrade.
There are several ways to verify if the upgrade was indeed succcesful
Check Versions table in the config and other content databases. If the table called Version
Check the Servers in Farm in Central Administration
Check the Site Settings for each Site collection
In the event some version number are not synchronized, try to run the following command
psconfig -cmd upgrade -inplace b2b -wait -force
In most cases, this should force version to be synced
