There have been a number of posts on the GreenButton here that indicate that MS/Linksys didnt really think through the real-world behaviour of people's extenders and their MCE machines.
If your MCE machine goes to sleep between recordings (this is a good idea, as most PC's are 200w of your electicity bill all the time they're on), or because of a timed sleep due to inactivity, the extender has trouble 'waking' it again when you want to watch TV. We leave our DMA2100 on all the time (because it takes about a minute to start up when the power comes on)This hit me with a couple of issues
1) The extender can't wake the PC (WOL doesnt work, but a directed 'ping' wake-up is supposed to) - but didnt work for our MCE machine. I solved this by using a Perl script on my Linksys NSLU2 linux box which is in an earlier post below.
2) Once the MCE machine was being woken when the TV was being switched on, we still had the issue that the extender didnt 'notice' that the PC was now on- and sat at the useless 'Extender Disconnected' screen - not very transparent.
The above issue is solved by simply pressing the 'Start' button on the MCE remote, this is handy because if the extender is at the disconnected screen ,or at the main menu, it 'just connects' if the PC is on, and also if it's already connected it takes the extender back to the main MCE menu each time.
We use a Harmony 525 Intelligent remote, and this can even be taught to 'send' a 'Start' key when the TV is powered on - the result is that the MCE home screen greets us every time the TV is powered on to watch TV... Perfect 8-)
So Linksys? how about a firmware update with proper Wake-On-Lan support? - and hey, while we're at it , how 'bout 'polling' that MCE machine on the network to see if it's there, and restarting the extender session?
Oh yes, then there's that irritating BRIGHT BLUE LED on the front - but black masking tape soon solves that one 8-)