Q: Warning: SUID file “System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/MacOS/ARDAg ent” has been modified and will not be repaired.

you can ignore that.

https://support.apple.com/kb/TS1448?locale=da_DK

When repairing permissions (which is seldom of any use anyway) uncheck the box "show details"

All you're interested in is whether the repair completes successfully.

Only if doesn't do you need to look at the results.

Even if you uncheck the box, the repair is not successful because you get:

Warning: SUID file “System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/MacOS/ARDAg ent” has been modified and will not be repaired.

Now, I don't know about you, but I find this might mean the repair was unsuccessful and because it's unsuccessul you need to figure out why and/or where the error originates.  So...on that happy note..

This error happened after I updated to the latest RDA from Apple. To track it down I did the following:

1. Clean install of OS X 10.9.1
2. Run "Repair Disk Permissions" - Nothing found
3. Update iTunes to latest (and theoretically greatest)
4. Run "Repair Disk Permissions" - Nothing found
5. Update iBooks (another great piece of work)
6. Run "Repair Disk Permissions" - Nothing found
7. Update Remote Desktop Admin.
8. Run "Repair Disk Permissions" - Warning: SUID file “System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/MacOS/ARDAg ent” has been modified and will not be repaired.
9. Run Repair Disk Permissions - Same results
10. Go to System/Library/CoreServices/RemoteManagement
11. Rename "RemoteManagement" "RemoteManagement-Bak"
12. Run "Repair Disk Permissions" - Nothing found.  I rebooted after renaming the directory and the system runs normally.

Now, I don't want to jump to conclusions here, but I somehow think the problem is in the RDA upgrade. I never had that error message before (starting with 10.7) and I didn't have it before the upgrade,  but I definitely had it after the upgrade.

Oh, as a side note: Before I renamed that directory and made the error message go away, I booted into single user mode and ran Disk Utility and had the exact same error message. I then booted from a USB install drive and ran Disk Utility once again, same results.

I may not be Einstein, but I know that 2+2=3.9999999 more or less...and this is a RDA update = error message.

As was said back in 2012, this is a status message and not an indication of a problem. Updates to ARD can cause the message to appear when it hasn't before and Disk Utility has not been updated to hide the message. You can ignore this message.

Regards.