Disable iTunes Match. Worked for me. Source: https://discussions.apple.com/thread/4556697?start=0&tstart=0
Jailbroken Apple TV + Remote 3.0 + iTunes Match enabled on Apple TV = Crashing
But I want to use iTunes Match, so why should I disable it :). It is better for me to use older Remote 2.4 and I can use iTunes Match on my AppleTV. Is it something new in Remote 3.0 which is worth upgrading?
Yes, disabling Match seems to have worked for me too. I also used the new version of SP to jailbreak the ATV again, but I don’t think the two are connected - I think disabling Match was the actual fix.
I used the remote app to play iTunes Match music so it’s not a solution. Especially as I paid for it too, I’m not turning it off.
So seems we just wait for a fix. Is there an update to this? Will the new season pass fix it, if so when’s it out, if not what else is in the works?
Kind of spoiled my Christmas party today 
Thanks
I just bought ATV Flash and wasn’t expecting this. I use iTunes Match and disabling it is not an option…
Just use the old version of the remote app. Works fine as long as you are using Remote version 2.4
And how do you suggest to downgrade?
Works fine with iTunes Match?
Even if so, again: I just bought this and was not expecting this. Even worse is seeing that this issue is 2 months old and still isn’t fixed
The issue may well be in the Remote app itself which is an Apple supplied app, so not amenable to being fixed by FireCore. I have seen references to this being an issue even on systems that are not jailbroken unless you are on the latest 5.1.1 firmware. If that is the case we are probably going to have to wait for a jailbreak of the 5.1.1 firmware before the issue is resolved.
I personally use the Remote HD app in preference as it offers significantly more functionality than the standard Remote app, and this seems to not suffer from this issue.
“The issue may well be in the Remote app itself which is an Apple supplied app, so not amenable to being fixed by FireCore”
I agree, although I think Firecore do need to investigate if they can fix it, and very importantly post an update here to let us know IF they are doing anything or not.
In my opinion this is a major issue using Firecore. The Remote app is extremely useful and I use it all the time.
By the way, does Remote HD allow you to browse and play music like the Apple Remote App? Or just a control to select items on screen? I use the Remote app for browsing and playing music so I dont actually have to be at the TV and have it off. If Remote HD does that then I will give it a go.
Instructions are on page 1 of this thread, or easily found by online search
Remote HD does allow you to remotely browse select music, however it is not comparable in function to the Apple Remote app for this purpose.
If I was you I would simply downgrade for the moment and keep using the old version of the Apple Remote app until this matter is properly resolved.
I should be more specific about the downgrade… the instructions imply you have the older version in your backup. I do not, as I upgraded ages ago and dont keep such old backups. Therefore how would one downgrade if they dont have the old version? You see the issue now! 
Sorry for asking, but is anyone replying to this from an official support? Has anyone from firecore commented?
Nope
I’ve sent an enquiry using the contact form of this page to Tech Support. Hopefully there will be a reply. You could do the same if you have interest on seeing this solved.
Cheers
I’ve posted a comment to this new blog post about aTV Flash Black 2.1 about the issue with Remote:
And a staff member has replied:
“We’ve tried that on a few different boxes and just can’t get it to break. If you are able to send in a diagnostic report and open a support ticket it may help in tracking down what’s going on.”
So I already use an older version of Remote (2.4), so I cannot reproduce this problem without upgrading (I don’t have enough time for this now). But if one of you already have this problem, please open a support ticket and send a diagnostic report to Firecore. As someone above mention, it could be an issue with incompatibility between Apple TV iOS 5.0.1 and Remote 3.0, not related to aTV Flash. But someone without a jailbreak should check this.
There was a Remote App update this morning and its fixed this issue for me! Wayhay!
Hooray!
@amityweb did it actually fix things for you?
I’m still getting constant reboots using iTunes Match with the jailbreak and latest remote app.
I think this is spreading around and giving a false sense of resolution…
As far as I can tell, this still causes a reboot of the ATV2 whenever iTunes Match is actually used.
I can confirm that I don’t see any reboot until I actually select an artist.