Greetings!I faced the following problem. When I add new attachment field and upload an attachment while adding or editing an item from frontpage form, everything works fine. But, then when I try to delete any attachment from the frontend....If Joomla's SEF engine is turned off - attachments can be successfully deleted. But when SEF engine is turned on... Nothing happens...I watched the response in Firebug, and here's what i see.
GET /component/k2/item/deleteAttachment/7/7   -  403 ForbiddenOnce again - this 403 error appears only when Joomla's SEF engine is on. Otherwise everything's ok.And it's a real problem for me.I need SEF urls! And I don't think that any 3-rd party engines like sh404sef can solve this problem....Who knows what's the problem?P.S. backend editor deletes attachments normally, even with SEF on.

I've found the solution via applying a hack to file
/components/com_k2/helpers/permissions.php

I'm not sure that it's good for engine's security, but i'm satisfied)

If anybody needs it too - just ask me and i'll post the solution here.