By the way, the headers the error message is referring to are http headers, not the header file in your theme.
I don't know what the "http headers" are, or where they are located.
After reading Sierra's suggestion I did go and remove any extra spaces in those files. I don't think there were any really that weren't always there. Anyway, it didn't help.
It's been a week maybe since I've done anything with my blog and today I got an email about a comment that needed moderating. When I clicked on the link to go and moderate it,
I got that same old error message. Then I tried getting into my blog as admin, and couldn't - same message. Went to dreamhost "manage users" or domains and clicked "visit" for my blog and got the same error message again.
I can get to my blog as a viewer like the general public but I can't find a way to get there as admin. using blog.priscillanhk.com/wp-admin just gives the error message now. I used to be able to get in using that URL. Seems like the only access I have to the "guts" of my blog is through FTP. That is still working - using Firefox FTP.
I might need a reminder of the ways one can get into their blog as administrator. Maybe I'm forgetting something. Dreamhost has a multitude of directories and such and I sometimes have a hard time remembering where I need to go to do things.
I would be happy to delete the whole blog and just start over - hopefully that would give me a clean slate - if I was sure it would work and knew how best to do it. It looks like I can delete the whole blog in the "Manage Domains" area - which I am able to get to.
Maybe I could use that delete and then later create a blog under the same domain - so it would end up with the same URL as it has now.
Seems like that should work.
Another option I guess is - but seems like a lousy one - I could start over by deleting all the blog content using FTP -(though they might take a long time and lots of effort) - or installing wordpress over the top of the existing one - would that erase everything that's there now? They warn to be sure there are no files there before doing a one-click wordpress install. Is that warning to prevent the user from clobbering her own data or is that warning given because the new install will get messed up if there are existing files in the blog folders?
I have copied all the text of my few blog posts and taken screenshots of the images I had posted - to remind which ones I used and where.
It wouldn't be hard to start over and just paste the text and re-upload the images as needed. I just need to be sure that I get a clean slate and get a clean new wordpress install.
Thanks again for helping me out!