Transmission problem

ok i have a 96 accord lx, the problem that i'm having is with the tranny. I would start up my car and put it in gear and it would run fine (fine meaning it would shift into every gear). But soon as the tranny get warm it would shift in drive but doesn't seem to want to into second,third,or fourth gear. I had the same promblem before and change the tranny and it seem to fix the problem. Then four months later the same problem happened again. Also the engine light came on and i did a self diagnostic and it had something to do with the TP Sensor (Throttle Position). The tranny also makes a funny whinning noise when i start up the car. Somebody told me that when you change a tranny your also supposed to change the tranny computer is there any truth behind that. Any help or suggestion would be greatly appreciate from anybody.

Have you checked the level fluid?
Btw, I dont think that there is a "tranny computer" so I would have to disagree with having to change it.

The whinning noise does it go away when car is put in gear?
It is not cheap to get done (say $100.00) but some dealers have a transmission flushing system that really works well, because all of the fluid is changed in tranny. This will most of the time remove any foreign particles from the whole system. As for the computer If you have a shop manual look in the electrical section and find the cpu. See if it operates the tranny shifting.
Something else is that the cables that operate the throttle body and trans shifting I think are tied together and if not adusted correctly will also cause problems.

yea the whinning doesn't stop when its in gear but it gets a lot quieter to almost you cant hear it

This could be any number of problems, the whining noise could be your front pump with exessive clearance between meshing gears, and this could be interrelated with your shifting problems. The tps problem may also be to blame. Your transmission reads info from the computer that the tps sends it, if that information is not there, some computer controlled transmissions go into a limp-home mode where it will only allow first (and sometimes second) gear, just enough to allow somebody to LIMP HOME.

Do you also get problems with your engine when you get the tps error?

yea on a weird note. I was messin with my car the other day, i drove it around the block a couple of time and it seems to be runnin fine, got into every gear. I even drove it for like 45 minutes and mashed the gas a few times and it seems to runnin fine. I just confused now.