Calibre 0.8.70, WinXP, and Nexus 7 (MTP)
Kovid, this follows on from the thread about testing your MTP drivers. As you know, that version worked for me with WinXP. As I know, you decided that Calibre would no longer support WinXP.
I updated to the latest v0.8.70 of Calibre, and something has broken between the two versions. Calibre could no longer see the Nexus even though it was seen by My Computer and WMP11.
I uninstalled Calibre v0.8.70 and re-installed v0.8.69. The older version recognised the Nexus immediately, and I was able to send books to the device. I checked, and the plugin tweak had survived the uninstall/re-install.
It is a pity that the new version no longer works with MTP/WinXP - it means that unless you can fix this for us WinXP users, I will no longer be able to update Calibre.