I just loaded the latest verison of Calibre 1.7.0 and when I go to "add" a book (just click on red "add" button) it quickly shows a windows explorer window (to select the file to add) and then closes the program. It does the same exact thing if I try to add a plugin to the program by choosing preferences > plugins > load plugins from file (it brief shows explorer window to find the file & then closes Calibre immediately). Running Windows 7, all latest win updates, admin privileges and tried uninstalling & reinstalling program and manually installing plugins via command line as well as turning off all antivirus software and tryied safe mode.....all with no success. Checked with the developer and he has no more ideas after checking all the things he wanted me to check (see here for list:
http://manual.calibre-ebook.com/faq....s-occasionally ). Please help. Thanks.