Henrik,
Yes, thinking a little further it really does need to be :

-turn on TXint (in basic), send from INT routine, then disable in TXint when done sending all.
And just be carefull not to conflict, ie..... turn off one send mode if the other is active, for TX and hwserout.
(just leaving TXint on without loading chars would just stop the works cold there)(dah)
Don