Thread:Project:Support desk/Cannot upload files since the update from 1.22.7 to 1.23./reply (6)

Your issue is caused by PHP's, a broken-by-design setting that does more harm than good. Unfortunately it seems that some people just don't bother reading manuals and enable that setting because "hey, it has 'safe' in its name, so clearly it must be good!". The PHP manual states that safe_mode has been "DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 5.4.0" (finally!).

I suggest you contact your hosting provider and provide them that PHP.net link and ask to have safe_mode disabled (and/or PHP upgraded to 5.4.0 or newer; either one works).