First of all this is a great plugin!
Unfortunately "Show on (all) categories" was dropped in Version 1.7 and this does not make sense to me. People with a lot of categories are now forced to create a float for every category which is very time consuming.
The options in the previous version were fine. Why change it?
Show on Homepage
Show on Posts
Show on Pages
Show on Categories
Show for Posts Only in Category (drop down)