A couple of things that might be causing the trouble.

You have TAG defined as ten elements but you erase 11
FOR Z=0 TO 10

Try removing the WAIT in the HSERIN statement. Triggers once then it has to WAIT for the second time data is sent to move on....

And I do not see where the USART is set up?

You may want to read over this
http://www.picbasic.co.uk/forum/show...3530#post23530