BibTeX, biblatex and biber ⇒ Multiple bibliography files

[Sagil]

I've been trying to use multiple bibliography files for an article:

\bibliography{data_mining, sampling}

However, it looks like only the first file specified is actually used, all other references are not found. Instead, I'm getting

Label `...' multiply defined

warnings for all entries in the first file. Looks to me like it is reading the first bibliography file twice. Any ideas how to fix that?


Edit: Nevermind, deleting the .aux and .bbl files and recompiling fixed it.