pkgin conflict with same package

["Jeremy C. Reed" <reed%reedmedia.net@localhost>]

# pkgin upgrade       
calculating dependencies... done.
mysql-client-5.0.96nb2 (to be installed) conflicts with installed 
package mysql-client-5.0.96.
proceed ? [y/N] 


Why would it conflict with itself? Shouldn't it just upgrade without 
this warning?

I have pkgin-0.6.3.1.1

mysql-client-5.0.96 is marked as non-autoremovable