First let me say that I have posted this on the Silicondust forum here: http://www.silicondust.com/forum/viewtopic.php?t=5096

I just got a HDHomerun this past Friday.  The setup was incredibly easy and I was up and running in no time.  I updated the Firmware to the latest and I downloaded the latest software.

On my PC I saw no problems.  On my extenders it was a horrible experience.  Stutters, green screens with pixelation and sound popping in and out. 

I that it was something with the streaming and networking.  Turns out I was sorta on the right trail.  I finally found this post, http://www.silicondust.com/forum/viewtopic.php?t=5096 and was able to get a work around.

So if I turn on Media Center on the PC and leave it on, the HDHomeRun works perfectly.  If I close Media Center both my recordings and watching live on the extenders is choppy and pixelated.  So in the mean time I am leaving Media Center up on my PC 24/7. 

Does anyone know of a fix for this?  I have Vista SP1 already installed (actually before I got the HDHomerun) so that is not fixing anything for me.  The other post mentioned a network stack prioritization issue.  Any ideas?

I had this problem on my new Dell machine I got yesterday. I ended up downloading the newest network card drivers (direct from Intel, not Dell). Installed them and all the problems you're describing went away.

Try looking around for an updated network card driver.

Got specs?
Full specs on the PC, make/model of router, are any switch(es) involved?  Is everything on a hardwire connection, or are one or more things in the chain wireless?

I'll say this:  messing around with the network stack in Vista is very much not recommended.  But, playing around with the NIC settings (namely, enabling/disabling flow control, as well as manual setting of the link speed) are worthwhile.

I did not think about updating the network card drivers on the PC.

This is what I have:

XPS 420	Intel® Core™2 Duo Processor E6850 (4MB L2 Cache,3.0GHz,1333 FSB)
Operating System	Genuine Windows Vista® Home Premium with Digital Cable Support
Memory	4GB Dual Channel DDR2 SDRAM at 800MHz - 4 DIMMs
Video Cards	Radeon ATI HD 2600 XT 256MB
Hard Drive	500GB - 7200RPM, SATA 3.0Gb/s, 16MB Cache 750GB - 7200RPM, SATA 3.0Gb/s, 16MB Cache (from NewEgg)
TV Tuner & Video Accelerator	Dual ATITV Wonder™Digital Cable Tuner with Remote HDHomerun

The router is a LINKSYS WRT160N Wireless Router. I also have a switch that is a DLink DES-1105 Ethernet switch.  Everything is hardwired.

I would rather not mess with the Vista stack either.  I am going to try and update my nic drivers first.

I also forgot to mention that FlowControl on the nic was enabled awhile back to help with extender performance.

If you have everything (extender, PC, and HDHR) spread between the router & switch, try moving everything to one and/or the other if possible- it's possible that one or the other isn't playing nice enough with something in the chain.  Likewise, try playing roulette with what's connected to which.
And, again, it may be worth playing with the link speed on the PC's NIC. 
Updating the NIC drivers would also be worth a try. 

Thanks Cup! I actually had everything connected to the switch when I first noticed the issue.  I moved everything to the router and nothing changed.

Where do I change the link speed on the nic?  In the properties?

I have to wait until later tonight before I update the drivers after all of tonight's shows finish recording.  I will report back as soon as I update and test.

I had a chance to update the nic drivers last night after everyone went to bad and the last show recorded.  I was only able to test for a few minutes but so far it looks like I have achieved success!!

My nic drivers were date 04/2007.  Dell had drivers on their site dated 10/2007.  I tried those first but the install did not seem to work.  I then tried the drivers from Intel dated 02/2008 and had no problems.

Thanks for your help guys!

So as a review for all future first time HDHomerun buyers:
1) Make sure your NIC drivers are up to date
2) Download the latest software & drivers from the Silicondust website, do not use the CD.
3) Download and apply the latest firmware from the Silicondust website
4) Proceed with setup as outlined on the Silicondust website

Also if you open media center on the main pc that can help for some odd reason or another.

Plucky,

That is what I was having to do to get it to work on the extenders.  Now that I have updated the firmware on the HDHomerun, installed the latest HDHomerun drivers and updated the nic drivers directly from Intel, I no longer need to open Media Center on the main PC anymore.

If you are doing that just make sure you have those 3 updates and you will be good to go.

No not doing that anymore just now it helped when I was first having the problem.