WDS orphan boot images problem

We have SCCM 2012 R2 CU2 installed.

All Boot images was removed, but SCCM still wants to add non-existing boot images (SC00006) in RemoteInstall\SMSImages, although that boot image not exists anymore. I uninstalled PXE and installed it again (successfully), but this doesn't solve the problem.

For this reason PXE is not working on SCCM server.

How to remove information of non-existing boot image from server?

Thanks for answer in advance!