I had the same Chromium problem with same description. Glad its not only me (sorry). Win7 Pro 64bit, with 64bit JRiv (24.0.37). Up-to-date Comodo Firewall and Emsisoft Antimalware.
I had a similar problem when I upgraded to MC24 (during the last build, .34) but somehow got it to work after messing with a ton of stuff. Going out of town in a few minutes, so can't help much.