Tested both on 12.04.2 LTS and 12.10, when attempted to change icons the progress stuck in a loop, continuously repeated itself, slowing the whole system down. No error messages were generated, hence am unable to provide any logs.

Reproducible: Always

Steps to Reproduce:
I simply put the icons to /usr/share/icons and also tried those available by default. Icons appeared in the icon manager, but when attempted to change, the above occured every time in both versions.
Actual Results:  
System slow-down, almost froze, progress stuck in the loop, icons weren't change properly, only some of them.

Expected Results:  
Icons should be changed immediately.

Cannot provide, as I uninstalled Kubuntu.