1) Welcome to the Party!
2) As you are obviously new here, I have some suggestions to help us all help you:
When you post, please post your entire configuration including (but not limited to) your installation method and vicidial version with build.
This IS a requirement for posting along with reading the stickies (at the top of each forum) and the manager's manual (available on EFLO.net, both free and paid versions)
You should also post: Asterisk version, telephony hardware (model number is helpful here), cluster information if you have one, and whether any other software is installed in the box. If your installation method is "from scratch" you must post your operating system and should also post the .iso version from which you installed your original operating system. If your installation is "Hosted" list the site name of the host.
If this is a "Cloud" or "Virtual" server, please note the technology involved along with the version of that techology (ie: VMware Server Version 2.0.2). If it is not, merely stating the Motherboard model # and CPU would be helpful.
Similar to This:
Vicibox X.X from .iso | Vicidial X.X.X-XXX Build XXXXXX-XXXX | Asterisk X.X.X | Single Server | No Digium/Sangoma Hardware | No Extra Software After Installation | Intel DG35EC | Core2Quad Q6600
3) The conf file entries for phones are only generated on the dialer to which they are assigned. If you change the IP of the dialer after creating it, then it no longer believes those phones belong to it (because the IP no longer matches). There is a specific method by which you must modify the IP in Vicidial, and I believe that Goautodial has a "quick version" to make it possible in the web interface. So check that out for the version you are running or run the ip updater script for vicidial itself. Plenty of documentation available for changing the IP of a Vicidial server, let us know if you can't find it.
4) IF you have not changed the IP of your server, on the other hand, there is indeed a cron script that runs and will check the admin->server flag to see if this server should be reloading its config files. In which case deeper troubleshooting may be needed. I note you did not tell us whether your system is fresh/recent or has suddenly stopped working after being in service.