In another thread, several people (including myself) had been having problems getting yak-on to connect when using TCP and not BES. I have been working with yak-on support to try and resolve this issue and they have released a beta software release to resolve the issue. This build will be incorporated into the main build within a couple of days according to support.

If you are having problems getting Yak-On to connect via TCP, you can download the beta at:
http:\\yak-on.com/staging/beta_1.10.19/YakOn.jad
(note: Softcentral gave permission to post the link)

This release is now working great for me.