All shares orders were cancelled during the last GLBSE update. I guess tawsix will put the SIN ones back up for sale soon.
bing: I think it's dividend_per_share = total_dividend_payout / ownedshares
You can use the web client to make dividend payments.
The total amount paid is divided over the sold shares.
That means that shares in the issuers account get nothing(this is by system design).
Nice! I'm one of those who likes to find errors in systems and you already thought of everything, perfect

Oh, btw, good work with the web-thingy!