Join Chat Room window using 100% CPU (just one core)

Hello! :)

I started using Polari yesterday so I don't know if this problem's already reported.

When I open the Join Chat Room window, my CPU's fan start working at maximum speed and the laptop becomes unusable while it's refreshing Freenode's rooms list. Things become smooth again as soon as the refresh finishes.

I think the spinner animation might have something to do with this but I'm not 100% sure because I didn't try to debug it yet.

Here's a screenshot for reference: