Ok, understood.
I am providing the following explanation is in case anyone else finds this thread, and perhaps does have an WMM issue..
WMM defines four priority "channels" on a wi-fi router for supporting internet access for different classes of applications (background=email, best-effort=web-browsing, video, voice).
When an Apple device talks to a router that supports WMM, the router is obliged to use these four priority "channels" and manage traffic contentions appropriately.
JRemote (on iPad) does not support these WMM capabilities, so it tries to download via the router's (default) best-effort=web-browsing channel.
Sometimes, when the iPad is using (or has recently been using) one of the higher priority channels, that causes the lower priority channels get so little resource that they become effectively blocked.
There are three possible solutions:
1) The real proper solution would be for MC to add support to JRemote for the WMM features, and request downloads via the router's voice or video channel respectively.
2) The work around solution is to either a) disable WMM on the router, or b) set the router so that its SSID only supports WMM best-effort. This directs all applications requests from the iPad to use the same best-effort channel, and this means that no other application has any special chances of blocking JRemote traffic.
3) A possible third solution (but don't hold your breath) might be if Apple tweaks iOS so that the higher priority WMM channel cannot block a lower priority WMM channel when the higher priority channel is not actually being used. It looks like Apple reserves the channel even if nothing is going through it. So it is a kind of a bug. But probably not high on Apple's to-do list though..
