I'm not actually sure, (maybe the moderators could comment?) but it might be that plugging the external blaster in might isolate the internal blaster. In that case you might be able to build a 'shield' from cardboard and duct tape so that only one box is affected.
Some companies (Tivo, Dish, DirecTV..) allow you to set different remote addresses to avoid this problem, but unfortunately I don't think Dream Media offer this.
This is a very good question that you have. With the new units the built in IR emitters are much stronger than they were on the older units. From what I know of the Dreambox DM8000 it will only work with IR, so RF is out of the question. If this is not correct you could put the unit that is not connected to the Slingbox into RF mode to make the IR emitter not change that box. The only other suggestions that I really have for you is to isolate the Slingbox 500 and the cable that it is attached to from the other box. Being that the DM8000 is only IR this may be a really annoyance and I am sorry about that but with the improvements in the IR emitter in the 350 and 500 it is meant to fill the whole room with IR light. Another thing you could try to do is to get a pair of our older IR emitters and try to direct the IR light more towards the correct box. You will still need to isolate the Slingbox 500 but you would not have to do that with the IR cable box.
Hope this helps,
Sling Moderation Team
Hey Guys thanks a lot for your answers
but I think that if you build in such a strong IR you should think it through. Some guys just liked the way it was. If it only had an HDMI. Over here in Germany this is the standard...
Is there a possibility that you could write an update to switch it off via software?
I don't understand that if I put in the external, the internal IR wont shut down. This makes no sense to me. It would be very kind if you would pass this through to your engineers. Maybe they can consider a solution for the 500 in the future.
I already tried the old emitters. It is now half a meeter away, how far do you think I'll have to get?