This is a potentially dumb question, but are you absolutely sure you're not just clicking the Quote button right next to the Edit button, since they're smaller and no longer have text on them? I haven't seen anyone else having issues.
Thanks kyro but no, I can clearly see the mouse over info box. "Edit Reply blablabla"
If I am the only one with issues then it is totally my problem, but it does worse with IE for me. With chrome it's only when editing a post with embed tags, with IE, the edit will make another post even if it don't have embed tags.
EDIT: HOLY Crup, it works now