I think that this is maybe related to tinymce. At first - what is language of your site when you use Russian characters? (I can reproduce this with my own lang set).
If Russian, check if your tinymce folder has in lang folder script for Russian language. It should be part of translation.
I admit, it's weird if one button work and second one not, but this change is done before e107 saving anything. You open source code, change title or alt and if you reopened it (without saving to database), result is wrong. This is reason why I think it's related to missing lang js file or bug in tinymce.