[Dx4win] MMTTY BUFFER ERROR

[WB1AEL at VERIZON.NET]

MMTTY was working in Dx4Win but now when I hit one of the buffer keys with
either the mouse or F key I get an error message.  
          Exception Occurred 
          Open – device already open

It works if I hit Tx button and free type in but not from buffers.

Tnx Shawn, WB1AEL