I doubt it. It sounds as though Insight have 'tweaked' the remote to send a different code to the standard one, and there is no way Sling could cope with that. I might be able to help though. What happens if you use the Custom Remote at Motorola DCT-6416 III PVR ?
Thank you for utilizing our answers forum here! I understand that you are looking for a remote that is not currently in our system. The best place to go for this would be right within our forum here, in our Enhancement Requests and Product Feedback section. We currently have a team working on adding remotes to our database and this is the place where they get their information from. Furthermore, you can always check in our What's New section to see the most up to date list of remotes, as well as any other Slingbox news.
Here are the links I described above:
Hope this helps!
The Sling Moderation Team