Frustration!

For reasons I cannot fathom, my home computers are refusing to let me post or comment on my own blog!
You can imagine how I feel about this.
Not chirpy.
I've tried downloading a new browser, Chromium for Linux, but it hasn't helped at all. I have to go off-site to blog, and that's not how I like to roll :-)
Others in my household are cheering the development, and I suspect them of subterfuge, but can't fathom how the could have kneecapped  my harmless little blog and certainly can't rectify it at all.
If anyone can advise me, I'd apperciate it very much.