[SD-User] Winkeyer USB - K3 - Unable to key my transceiver?

[ON4WIX]

Hello All,

Probably a stupid question from a newbie to transceiver keying, but here she 
goes anyway.
Using a K3 here with a Winkeyer USB and an HP Vista PC.
My Winkeyer USB shows up at port 6 on my PC while my K3 is connected through 
port 5 which is a generic serial port.
Using the PORTS command I have selected COM 6 as my radio 1 CW port and COM5 
as my radio 1 control port.
When firing up SD (v 14.29) I can read my K3's frequency OK within SD.It 
tracks VFO changes consistently.  However I'm unable to key my transceiver. 
I've got CAPS LOCK on so I should be able to send standard exchanges when 
pressing my F1-F8 keys. Here's what happens: when I tap F5 (caps lock on) 
the message "CW keyer, ESC to quit" appears in the SD screen for a few 
seconds and then disappears. My radio does not go into TX however. Rig 
Control is set to "on" in SD.

I'm probably just missing something elementary here. However, as I'm new to 
TRX keying I'm at a loss here. RSGB Test starts in 15 minutes and it would 
be nice to have some automated keying here.
Any help will be very much appreciated.

73
Glenn ON4WIX / OR4W