After your dictation travels from your iPhone to your PC, myEcho uses the Windows Clipboard to transfer the text to applications like Microsoft Word. If you're running a background application on your PC like a clipboard manager or a launcher that watches the clipboard like "Executor," myEcho won't be able to use the clipboard. This isn't a limitation of myEcho, but rather a side effect of how those applications "hold the clipboard open" and never let go.
In the case of the Executor application, go to the Settings dialog with Executor, then the Misc tab and uncheck "Use clipboard sniffer." After this feature is turned off, myEcho will work great!