As background, I am working to install COWOA (beta 2.7) on a v1.5.5a site. I've had to switch back and forth a couple of times between the new files and my backup (through cpanel). The first couple of switches were fine with no issues.

However, after a few passes, my admin menu CSS is blown out. I've tried multiple restores, and removed both the admin and includes folders before the last restore. My main store files appear fine.

FWIW, I had a bookmark that goes to my admin, but doesn't go to the https version (made during pre-cert development). The CSS there works, until I click something and it shifts to https.

I've also looked at file/folder permissions, and tried the htaccess files. No luck there either.