Help! Can't post comments anywhere

Update:
I'm working on fixing this problem by using Google Chrome Browser 5.0
Looks like this may solve the problem, as opposed to using FireFox 3.6.8

Tech Note:  trouble with posting comments.
I've read through a bunch of tech stuff on this like
how to fix posting or comment problems for people
who visit your blog.  I still can't post comments
even on my own blog.

Non technical description:

Well the title of this post pretty much says it all.
I know Im not allowed to post comments at just any place.
Some blog owners will only accept them from people they know.

Non the less...
Even when surfing a blog that says "we don't get enough comments"
or "please post comments to help with this blog"
I still cannot post a comment even though I've put a few
sentences in the little box and clicked the "post comment" button.
Ive gone back and checked to see if my comment showed up
anywhere on that blog.  No luck!

Maybe I need to check on the Atom feed thing?
At the moment taking atom feed links seems to
result in a question like do u want to subscribe to this post?
Thats for email notification of updates on a blog right?
Don't think I need that.  Is there something else I need
to do with atom?