Picture Uploader after Migration to Linix

I just migrated from a Windows to a Linux server and now I have a problem uploading images. I’ve searched through many forums saying it is probably the permissions, however I have tried all form including 767 and pictures still won’t upload.

I think it might have something to do with .jpg and .JPG image ending, is there a difference? I’ve tried all kinds of things but I can’t figure it out. Right now I am uploading with an FTP and using a link to use picture in my posts.

Any ideas on how I could fix this?

Thanks!