Ok, now we're getting somewhere... Looks relatively normal so far.
All other things equal, I'd say something 'upstream' of the XPORT module is messing with your data, but that's just me and I'm guessing.

Get rid of the STR modifier in your SERIN statement and try just reading RAW data/numbers/characters/etc.
What is HSEROUT going to? Right back to the XPORT module? Is the feedback from the XPORT/PIC how you are verifying that it's sending/receiving data correctly?

And we still haven't seen your REAL code