serious permission problems

My 1.3.7 install has worked with no issues until today, when I could not edit a product description without getting a permission denied error. Similarly, when I try to upload an SQL patch, I am denied permission:

'You don't have permission to access /xxxx/admin/sqlpatch.php on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request. '

I have changed permissions on sqlpatch.php, cleared cookies, emptied cache and temporarily removed .htaccess, all to no avail. Any suggestions?

1. What did your host change? (you said it just suddenly started, right?)
2. What are your file and folder permissions in your /admin folder?

Admin folder is 755. I set sqlpatch.php to 777 as an experiment, but no go. I note also from the forum that there may be a problem with the extra_pages module, as the is a second version which refers to a fix re: the sql file.

But that would not explain the continuing problem with entering product information. I'll ask if there have been any changes. Thanks.

Solution: since my host made changes, I now must have

SecFilterEngine off

in my .htaccess file.