Did you install the required IOS for each program as well? MPlayer_CE will need a version of IOS202. I recommend using Hermes' V4 cIOS installer, and installing cIOS222 using an IOS38 base. WiiMC uses the AHBPROT feature of the latest HBC for low-level DVD access and IOS58 for USB2 speed. So you need to have HBC v1.08 installed and and should have IOS58 installed. You can get the HackMii installer for HBC here, and a great IOS58 installer here.
"FTP Server doesn't work for Ethernet-Adapters (maybe for some Wifis too) if you install IOS202 v5 based on IOS57. Also there is no Channel list in the StartMenu with that.
It is recommended to use the very old Hermes IOS202v2 base 36 merged 60 for the FTP to work. You'll have all features of WiiXplorer with it. If this doesn't work try another variant of it like v4 base 38 merged 60. If you don't want the old version installed on your Wii (which gives no disadvantages btw) live with FTP Server not working!!"