For clarification and to make it easier for others to follow along...
You are using phpVMS 5.5.2 - simpilot version
crystal and crewcenter are 2 different skins - they are not both crewcenters
You want to use the crewcenter skin (looks like the Mark Swan version) - but schedule search doesn't work
When using the crystal skin - schedule search works
Sounds like your crewcenter skin is not installed correctly. Did you replace all the .tpl files with the .php files found in the phpfiles folder - found in the crewcenter skin download? Have you made any edits to the crewcenter skin files? Did you double check that you followed the crewcenter skin installation instructions?