Just within this hour it started to work again. But it still had glitches. After I posted my blog post, it didn't appear on the homepage for a time even though it sent out announcements about the new post via email subscription. People could access the post via their email by clicking on the link, but if someone went to the blog/homepage, the post was invisible. It seems OK now (after I went back to WordPress & published it again), but this is another strange thing to notice/report.
To answer some of your questions...
How are you connecting to the internet and to WordPress.com?
I am at home with high speed cable internet using a Mac laptop.
There maybe be problems with your ISP and/or with the proxy servers.
There should be a proxy server if I am going straight through wordpress, no?
I'm writing on my blog through the wordpress dashboard with going through another source.
Which browser and version of it are you using?
I can look into this, but it (wordpress) is allowing me to submit tags & links to blog posts now. So do you still think it can be my browser?
Do you have third party cookies enabled?
I don't know what this means. Sorry.
Is your browser version up to date? Flash up to date?
I can definitely update them if you think I should.
It does seem like it's a problem on WordPress' end. But I will do anything you suggest to keep this from happening again.
Thanks for your help. I appreciate it.