I use domain mapping to force a site to https, and when I do, I can't upload any media files

I use domain mapping to force a site to https, and when I do, I can't upload any media files. I am also using smush with S3 offload. If I switch to HTTP then files upload with no problem. Occasionally I will try to login via https and I will get a 500 error, then if I just get rid of the s and login under HTTP it will let me login and then redirect me to https and everything works fine.