The "split into grid" dialog box doesn't really allow you to work intuitively. One reason is that the Total (size) fields update the associated grid AS YOU TYPE, which makes for a very confusing experience. The best way for the Total field to behave would be (1) to update the associated grid only when it loses focus, and (2) to increase or decrease to reflect the total size ENTERED, rather than forcing the other numeric values to FIT into the original size of the rectangle you started with.

To work around this, you can enter the rows or columns, and then enter the gutter size, and then USE THE UP/DOWN ARROWS to adjust the Total size field(s) until the Column Height or Row Width field gets to the value you want. This is an odd way to work, but it prevents the Total field(s) from setting the other fields to unwanted values.

For a detailed video on what's going on with this feature, see http://youtu.be/di-BQVNdBQs. For a very brief summary of this technique, without narration, see http://youtu.be/x_g1sZJoJVI.

Allen

Good point. I made the videos using CS6, which has had all its dialog boxes rewritten. I suspect that we may run into a few other little changes that happened when Adobe updated to their latest user interface platform. I should have mentioned CS6 in my original comment (it is mentioned in the video tags).

The keyboard arrow keys in CS6 work as they always have, so they seem to be an identical alternative to using the little UP/DOWN arrows in the panel.

Split Into Grid is excellent feature which allows me to create evenly spaced guides with gutter. I have detailed step by step tutorial here http://goo.gl/PaoiP

And by the way, this instructions are not allowing me to cut nothing at all.