iPad / iPhone home networking problem

Hi there I have been struggling with this problem for the last week and it’s driving me mad! Several months ago I installed Serviio on my PC and the Airplayer app on my iPad. They immediately and successfully talked to each other and I could access moview, music and photo files over my wifi network on my iPad, from my PC's hard drive. However when I last went to use it, Airplayer had...