I was troubleshooting my connection as well using this forum, but have not been able to fix my issue.
I have had MobiLinc installed on my Droid for maybe a year now. A few weeks ago it stopped connecting saying trouble connecting to the lighting controller. The only thing I can think of was that I updated ISY to the new official release.
Create new profile in MobiLinc (MobiLinc did auto-find my ISY instantly)
Recheck all typing and settings
Restart ISY (both telnet reboot and physically toggling the power).
Nothing has solved the issue yet. I did in the meantime get a new phone and have not been able to get MobiLinc running there either. FWIW I also have Conductor and that program did not experience any connection issues via LAN or WAN, through the ISY updates, and over to the new phone as well.