Q1: The new Usb Net Power 8800, is 6amp, can we get it in 6.5 amp or can the 6amp be use in 6.5amp situation?
Ans: 8800 is made with a 10 Amp design. Aviosys uses 6Amp fuse limit the power consumption but it can support up to 10amp. 
You can use a higher fuse, we recommend not to use the device at its limit for safety purposes.

Q2: My customer cannot get the 8800UK to work. He has loaded the driver and the application software, on his XP machine. When he plugs the 8800 Uk into ma USB port all appears fine. When he opens the application  the device is not detected?

Ans:Can you please have the client provide information regarding his OS platform?
Also this is what I recommend he can try. He can try to download the latest version of the driver from our website at this link.
http://www.aviosys.com/downloads/software/usb_power.zip

Then do the following:

1.) Make sure that the USB net power is unplugged and Uninstall the current firmware
2.) Install the firmware from the link provided. Sometimes it may take a few minutes to install the driver.
3.) Plug in the 8800 and it should be detected.
4.) Then copy the 8800 software onto the desktop of the computer