I had a very similar error and tried FreeMind_1.1.0_Alpha_1.dmg but ran into the same/similar crash. I downloaded FreeMind_1.0.0_RC_5.dmg and it works as well.
Process: JavaAppLauncher 
Version: 1.1.0_Alpha_1 (build: 0) (1)
Code Type: X86-64 (Native)
Parent Process: launchd 
Date/Time: 2013-12-19 20:15:49.433 -0600
OS Version: Mac OS X 10.6.8 (10K549)
Report Version: 6
Sign up for the SourceForge newsletter:
You seem to have CSS turned off.
Please don't fill out this field.