Visualization become wierd after server reload. Drawing/removing frame takes a very long time, and it can take very strange forms. If you restart the server while this bug occurs, it will work fine. Somehow, restart toggles this bug.

This bug happens only on 6.4.1. 6.4.0 seems fine.
I tried Bukkit 1240 and 1317, no difference, empty "Plugins" folder also doesn't do anything, bug still occurs.

Video proof: http://www.youtube.com/watch?v=SA24Atc34nY

UPD:

Replacing visualize.class version 6.4.1 to version 6.4.0 fixes this bug.

fixed in 6.4.2. It was mixed up visualization config variables.