Would it be better to do something like this and get rid of the WAIT?
Just Grab the first byte and see if it's for me, if so process, else Exit Interrupt....

'Receive Interrupt
Receive:
'Clear the buffers before anything
GOSUB ClearBuffers

'Instead of waiting, grab the first byte and see if it's for me or Exit
HSerIn Timeout,ExitRx,[BufRX(0)]
If (BufRx <> MyID)
Goto ExitRx
End If

For Cnt = 1 to 7
HSerIn Timeout,ExitRx,[BufRX(Cnt)]
Next Cnt

Gosub ProcessData
ExitRx:
@ INT_RETURN