It has started to shift hard between gears

Internal pressure solenoid could be failing.

Wait for saturntech to chime in. I read a new/rebuilt solenoid pack was the best route to take and dont drive it like that or damage can occur.

Just to add to this one a hard shift is caused by too high of line pressure. The first thing I would check is if the line pressure fuse is blown in the underhood fuse box. If its not then we have to do a high low line pressure test which is pretty easy to do. You just need to get a transmission pressure test kit to hook it up all you do is unscrew the transmiisson temp sensor. Then screw in the pressure tester adapter my gauge set is under 75 and really nice and would be cheaper to do that then take it somewhere to have it diagnosed. As you can see when you take it to a transmission shop they just want to rebuild or replace the transmission. Which isnt the correct repair its a easy transmission to repair and diagnose but a lot of people just dont know how to fix or diagnose them.

Here is the pressure tester i have

http://www.amazon.com/gp/aw/d/B000R5G0DO/ref=mp_s_a_1?qid=1330278367&sr=8-1-spell

Too much pressure that's your problem you need to do a pressure test to see if its a pressure regulator issue bad line pressure actuator or bad wiring.

So have you checked for codes yet?You could have a bad valve body line pressure actuator or a bad harness to the transmission.

When you put it in reverse is there a delay does it bang or go normally in reverse?

There is probably a pressure issue causing the problem

Also have you checked to make suret he battery cables are clean and tight and the alternator is good?

There could be a loose terminal to the inside fuse box that will cause some wild things to happen. Few people know about it unless you have been working on Saturn's for years.