What I'm about to say is going to upset some, but here I go. You can name a backup anything you want if you use.........ROM Manager. It will get the MD5 sum right. You still can't have any spaces though.
For further info on what YOU can do, and what you need to avoid doing, read this:
The Truth About ROM Manager
I have the Premium version just to keep the thread up to date. Everything is true and correct and up to date.
Quit being scared of ROM Manager. It does have some very good functions, like: Being able to rename and delete a backup, downloading the latest Gapps,etc. Everything is spelled out in my thread.
I personally don't think the premium version is worth buying, but, it will allow you to do automatic backups if your a flash-a-holic. You can also use the premium version to flash any ROM if you first download obijohn's update_wiper_1.3.zip and put on the sd card. These are things much better left to doing manually, hence no need to pay the $5.00+ the dev want's for the premium version.