Need feedback: non-Sony ebook software & borrowing ebooks from library (Overdrive)

[Eugenie]

I'd like to know if anyone with a recent Sony model (PRST, PRS-650/550, PRS-600/500) uses other ebook management software (such as Calibre) instead of Sony's own Reader for Mac/PC.

My preferred ebook manager is Calibre. Calibre works fine except when I borrow ebooks from the local library via their Overdrive service. When I import them with Calibre, I can't access them on my device. (I get a "Protected by Digital Rights Management" error.) But I CAN access them on my device if I import them using Sony's own Reader software.

Note that if I borrow ebooks from a service other than Overdrive (such as EBSCOhost), I don't have this issue. I can import them with Calibre, and I can access them just fine on my Sony device.

It's only Overdrive that gives me a problem when I'm using my preferred ebook software (Calibre). Is this typical for Sony device users who have done the same, or am I doing something wrong?