Use the Remotes in RF mode, and while setting up one, turn the other box so it doesn't receive IR signals from the remote then each receiver will be set on its own remote and will work side by side.
You will need a RC64R or another model 23 something, there should be a FCC sticker on the back of the remote if its RF capable, if not D* can supply them and occasionally Circuit City/Best Buy will have them also a local retailer. Its a crap shoot whether or not the box has a RF remote.
These remotes are a tad bit slower responding but would solve your issue aside from going to IR to RF converting universal remote system with IR eyes. As far as the TV's volume, not much you can do there aside from manually setting the volume, code 10811 only works IR. If you can control the volume separately with the Samsung remotes use those ad program teh remotes TV for 10154 so you don't accidentally change the volume.
It is possible this may help you as well and add to the dual HD TV's in 1 room cool factor
http://www.logitech.com/index.cfm/remotes/universal_remotes/devices/374&cl=us,en
It comes with 4 dual-IR emitters so you could set it up as HR20, H20, Samsung1, Samsung2 and run everything independently and on 1 remote.
Also found this by
Edmund
Yes, cover one receiver as you switch the other to an alternate address.
Start by programming code 00002 to AV1 or AV2 on the remote:
1. av1 or av2
2. press and hold MUTE & SELECT for two blinks
3. enter 0 0 0 0 2
slide back to the directv device on the remote and
enter the menu of the receiver:
1. menu> parental, fav's, & settings> system setup> remote> receiver mode>
2. you will see either Directv or AV1/AV2, click whichever to reveal both
3. choose AV1/AV2, the remote will stop controlling the receiver, slide to av1 or av2 whichever has code 00002
4. press done and exit the menu
Keeps teh remotes in IR, But still doesn't solve your TV volume issues.
