"Incremental recovery point" option is greyed out when trying to manually "Run back up with options"

Any advice on how to facilitate manual incremental back ups when "new recovery point set" and "independent recovery point set" are the only options given? 

I've seen a couple of older closed threads that touch on this topic, but it seems that the individual with the problem had the ability to select "Incremental recovery point of recent changes" and so any potential solutions to my problem did not end up being discussed.

 

 

 

I currently have three base image backups, one for each hard drive.  Running Ghost version 15.0.1.36526 on 64bit Win 7 Pro SP1

 

When I run a manual backup on the smallest of my three drives (OS only), it allows me the incremental option, and it runs quickly and without a problem. 

Also, separate question - can I use a higher compression on an incremental than I used when creating the base?

Thanks!