[ouzal]

Thanks for your support, I tried your method and managed to authorize the T2 with Sony Reader, but this causes ADE to loose its authorization (means I can no longer download .acsm with ADE, as I get error "check activation" whenever I double click a .acsm to download it)

I can "deauthorize/ then authorize" ADE and therefore get again the ability to download .acsm, but when I copy the downloaded ebook to the T2 eReader Download folder, the ereader can't read it and gives error:" Protected by DRM" (so it seems that T2 considers Sony reader authorisation to be different than ADE authorization, hence the DRM error even if it's authorized)

I managed to read one ebook from the T2 by doing the following:
authorize ADE >>download .acsm via ADE >>authorize T2 via Sony Reader (ADE now looses authorization) >>copy ebook to T2 and read it from there.
But this method is not practical at all as I'd need to always authorize/deauthorize ADE and Reader every time I want to upload a book and I'd loose access to all the books previously uploaded