I think you are missing something, as any time I have used the method you described, I am able to edit the text box and change what the title says. I assume you are using the method INSERT --> TITLE. This should pop up with a box to allow you to type in what your title is, or if you have entered one in the map document properties, automatically populate that initially. After that, its a simple double click (or right click, properties) to bring up the properties window. Then under the text tab, and the space below where it says text, you just enter in whatever title you want.
I use data driven pages sometimes, so there might be some coding in that area, that I just clear it out as I generally don't want it. You might also want to change in document properties though, just to be safe. To change the appearance of the title, you have to click on CHANGE SYMBOL. Don't know why they just don't enable you to do it from this menu, but oh well, it is what it is.
You could also just use a regular text box and do the same thing as well. Hope this helps.
