If you have problems follow these steps.
CW Skimmer Frequency Display
If the frequency display in CW Skimmer is incorrect then enable Diagnostics in the console's CW Skimmer Options window. When enabled all commands received from CW Skimmer and the replies are logged to the default debugger, you can use DebugView to see the diagnostics.
The command format is TS-2000 (as selected in OmniRig above).
With the console tuned so that the lower displayed frequency is 14.004 MHz the diagnostics should show:
SDR-Radio.com @ 15:49:39.702: Skimmer Serial> Skimmer: command = 'FA;', reply = 'FA00014004000;'
SDR-Radio.com @ 15:49:39.702: Skimmer Serial> Skimmer: command = 'FB;', reply = 'FB00000000000;'
SDR-Radio.com @ 15:49:39.924: Skimmer Serial> Skimmer: command = 'IF;', reply = 'IF00014004000000+00000000000020000000;'
If you do not see the diagnostic strings displayed several times a second then the serial port / OmniRig configuration is not correct.
CW Skimmer Waterfall
Remember, only use this virtual audio cable for the CW Skimmer connection. Do NOT use it to send audio at the same time. If you ignore this rule you may see odd / wrong / mysterious displays in the waterfall.