I just noticed that your code has you powering up the TX and then sending straight away.
I don't think I've ever had good luck doing it like that. I've always given my TX module a solid 5ms to stabilize before sending out the preamble.
But that's just me, and that's the only way I've tried it. It might or might not be alright to transmit right after power is turned on.
And based on what you are saying about changing the baud rate numbers according to Mr.E's calculator and the problem getting worse, I'd still be inclined to think that your oscillator is off. Yes, your PC can receive it, but maybe it's able to receive 'sloppier' serial than the receiving PIC can.