After SP1 we had the same/similar issues in our environment. Here are the steps I used to fix PXE on the DPs and get OSD running again:
untick the enable PXE checkbox on the distribution point. Answer yes that you want to remove the Windows Deployment service.
remove boot images from your distribution point
After 5 minutes delete %windir%\temp
check with server manager. If WDS is done uninstalling there is a reboot pending. Reboot.
check if the remoteinstall folder is located on your system. If it is delete it. If it fails to delete due to permission issues with the SMSTempBootFiles path, delete all folders except that one and then rename the remoteinstall folder something else.
reboot
Add the PXE point again by checking the box on the distribution point properties. Check the distrmgr.log and see if the remoteinstall folder reappears..
Replicate the boot image to the DP again. After they land you can try running an F12 and it should roll smoothly.
RE: the old remoterinstall permission issues, this seems to be the root cause of why PXE broke on all our DPs after SP1. As to why the permission error occurred, I cannot say but will continue looking for the root cause.