The security token error has been around for a long time and just randomly pops up (usually on attachments). Likely, its something to do with the specific styles as they are heavily modified. I dont think we even have a default (non modified) style available to test...BUT, thats gonna be my guess...or a VB system file is corrupt or missing but I'm gonna guess its the style.
As for the file attachment....you tend to post really nice pics so I'm guessing they are huge file size (by VB standards)...so its possible the error is from the file being too big. Tho I believe I have no limit on attachments but its still possible the site is flipping out.
Let me tweak a setting to see if it does anything...guessing not, but worth a shot.