Not able to modify products after 1.7.3 upgrade

[Suw]

Hi,

I've tried upgrading from 1.7.2.4 to 1.7.3 .

First it freezed at database upgrading, but front-office ok and the back-office interface seemed new. Since then, I haven't been able to add, edit, duplicate or save a product and the pages are taking an incredible amount of loading time.

I"ve tried to restore back my FTP and database to a week earlier, re-completed the 1.7.3 update (you have to disable all modules and current theme) et re-restore back to a week earlier... the probem is still there. Chrome dev tools seems to indicate a loading problem near the theme files but it wasn't there before the update.

Does someone know what causes these problems or how I could diagnose them ?

Thank you very much !