It seems ridiculous to open new topic for the same problem, but... forum rules.
It seems also, that the new wp 3.7.1 has problems with the media uploads. The last topics on the forum are realted to the same problem.
Here we go with my one:
wp-3.7.1(installed and reinstalled)
Theme - 2013
Plugins-only "Ozh' Admin Drop Down Menu"
Directories wp-content, uploads, 2013,11 have permission as following: 755,755,755,755 and images - 644
I have checked and unchecked the Settings-Media-"Organize my uploads into month- and year-based folders" ( according to an other user this worked for her).
What else I have o do in order to upload images to Media Library and to be able to see them?
Thank you very much for your help!