Previously activated DRM in Aldiko on my android tablet is no longer working

I have previously activated DRM in Aldiko on my android tablet with no problem. I imported a new ebook into Aldiko yesterday, with no problem for this book, but the DRM on all my other previously purchased ebooks was then de-authorized. When I try to open one of these old ebooks, I am asked to activate the DRM, but if I login using the same Adobe ID used to purchase the ebooks, and which previously worked, it fails to authorize the ebooks. I have tried uninstalling and re-installing Aldiko, and deleting and reimporting the ebooks, but nothing works... Any help would be greatly appreciated.