Boiken, 45 users on a single machine, that poor machine must be begging for death by now
You need to move into clusters ASAP, if you`re dialing in predictive mode you`d likely need 2 dedicated dialing server for that sort of load and a dedicated web server (plus the obvious MySQL).
Other folks experiencing issues, have a look at the Vicibox install guide (
http://download.vicidial.com/iso/vicibo ... nstall.pdf ) it contains some excellent guidelines regarding capacity. Whatever you do, remember that Asterisk, hence Vicidial, scales horizontally, not vertically, meaning more machines instead of bigger ones.