Deleting folder doesn't increase available disk space???

Thanks e.h. green, I've had this exact same problem before, and deleting the trash had fixed it. It's now my "standard operating procedure" to empty the trash before doing this operation (the problem is happening during a manual back up to an external hard drive). I don't know why I'm having this problem even though I've emptied the trash in this case. Thanks anyway for your reply.

--John

Thank you Klaus1, but I'm not sure how the page you linked to applies to the problem of space not being freed after a folder is deleted.

Also, I don't know what a Spotlight index is, what it means to "rebuild" it, or why that would fix the problem of space not being freed after a folder is deleted.

Any further explanation you could give would be appreciated.

--John