Backup Exec cannot restore from tape

Info:

Server: HP ProLiant DL380 G7

OS: Windows Server 2008 SP2

Software: Backup Exec 2012 updated to the latest version

Hardware:

• HP LTO4-Ultrium 1760 - tape drive
• LTO-4 Ultrium RW Data Cartridge (C7974A) - tape

I have to restore a server. What I got is the SDR-CD and the .dr File. When I start the server everything works fine, but then when the restore starts it says "Rewinds the medium" two times and then the tape is ejected, so the restore cannot begin.

The SDR-CD is one and a half month old and the .dr File, too. I don't know exactly from what time the backup on the tape is, I just know that it is a recent backup not older than two weeks. So I don't understand, why the restore doesn't begin, although I have the SDR-CD and the .dr File.

So my problem is, why the tape always ejects.

Thank you in advance for your answer