Hyundai Repair: 2003 Tiburon Auto/shiftronic tranny problem, range switch, couple seconds

Question
I have an issue with this 2003 Tib. When you first start the car and drive it, it will drive fine up until 3rd gear where it will just rev and basically get stuck in, which i'm assuming is safe mode. If you try to restart the car it will go back to first gear, or so it says, but the car will still just rev and in order to go anywhere you need to pin it to redline and wait a couple seconds before it engages and finally takes off. Now i'm going to throw a new transmission in it but my question is, could it be something other then the transmission or does it sounds internal?

Answer
Technically, the problem could be in the control module, but I've never seen (nor heard of) these symptoms being caused by the TCM.  

I'd recommend checking the fluid level and range switch just to be safe.  A defect in either can cause the transmission to act as if it's in neutral in certain situations.  These are rare, but can cause the symptoms you describe.  Otherwise, it's pretty much guaranteed to be internal.