I have contacted Amped and got this:
---
A customer support staff member has replied to your support request, #498111 with the following response:
Apple Home Sharing does not work on extended networks, but our products are compatible with apple. We are aware of this issue and trying to work on a fix for this issue. At the moment there is no fix for this.
---
I questioned the "compatibility":
'I don't know what you mean by "our products are compatible with apple". AirPrint (or any kind of printer) does not work. iTunes does not see the iDevices, and the Apple TV does not see the computer where the music/video is.'
Note: I am having a similar problem with Windows and printer's SMB broadcasts. I think they do not repeat any broadcast messages, so no "discovering" is possible, ever.
If you guys look at
https://discussions.apple.com/thread/2708968
you'll see that the AVM folks have already fixed their Fritz WLAN Repeater.
Unfortunately that one is not for sale here in Canada.
Please note that the problem is only with discovery (which relies on broadcasting). In the case of my MacBook although it cannot discover the printer or my mini I was able to print using te printer IP address. But that is not possible for iPad and iPhone, they need AiirPrint. The repeater has a good signal strengh and works very well with streaming. A shame it is basically useless on an Apple-based environment.