[jackbrown]

I have a very large collection of ebooks in which the files are titled in the style: ISBN.Press.Name.Title.of.book.pdf

About a third of them have an 'x' as the final 'digit' in the ISBN. When I try to bring them in to Calibre, the program strips out the final 'x' from the ISBN, rendering them useless for the purpose of metadata lookups, which is the main reason I am using Calibre.

Is there a simple way to reconfigure the import plugin so that it doesn't remove trailing 'x's from ISBNs? And why does it do that in the first place.

I am running version 0.8.4 ; I tried 0.8.5 but the metadata lookups have pretty much stopped working altogether in that version, so I downgraded again.

Sample title:
019280104X.Oxford.University.Press.USA.The.Oxford. Dictionary.of.Slang.May.2000.pdf

Calibre parses that ISBN as:
019280104

When you click on that ID, the worldcat lookup obviously finds nothing.

EDIT: I should add that right now the regular expression for importing is set as:
(?P<isbn>[0123456789x]+).(?P<title>.+)
which should allow the 'x' to stay, but calibre is nevertheless erasing them from the 'ids' field, and leaving only the nine digits that precede the 'x's