I love using "Todo" from Appigo on my iPad. Recently it stopped synching, probably due to a software update on either my laptop/desktop or on the iPad itself. Efforts to reinstate synching proved mostly futile.
I finally got it working again after checking a few things (in no particular order.)
1. Verify the IP address is the same on both the iPad and Laptop. Actually the last field of the IP address can be different:
PC: 192.168.1.167
iPad: 192.168.1.69
2. Verify your PC firewall is not blocking Appigo Sync. Find out the port used by Appigo sync from the preferences screen. Then enter the IP address and port number into a new web browser window.
Example: http://192.168.1.167:51438
3. After doing both, my iPad could still not "see" my laptop/desktop. So I did a manual configuation in Todo, Synchronization. Voila! I was able to "see" my iPad on the PC client and I proceeded to authorize it and re-synchronize.
All appears to be right in the world again!