Shrinking text in Google Hangout

I ran a game using Roll20 in a Google+ Hangout. My browser is Firefox 12.0 and my operating system is Mac OS 10.6.8 With the map zoomed to 50%, I wrote on the Objects layer with the text tool. The type came out rather small. Clicked with the tool to write a second thing in another spot, the type was smaller. Did it again, got type that was smaller still. Did it again, got an indecipherable little smudge.

I had the same with Roll20 on roll20.net

That's very prompt. Thank you.