Incremental Restore asks for next volume

I am trying to restore my OS from an incremental backup. I stored the OS 2 times: 1 time fully, and 1 time incremental (this is the OS with important updates). When I validate the archives, the full-archive validates (and restores) perfectly, but the incremental archive asks for the other volume (depening on which TI version is used it validates first and then asks for the next volume or just asks for the next volume outright).

How can I restore the incremental backup? Why doesn't it see the original backup? There is no file-corruption (I keep MD5 strings of my validated backups). The harddisks are fine too (chkdsk reports no errors, tested with multiple HDD's). Even my rescue media is screwing up.