I've always been paid when it hits 0.01 btc... I don't know about it staying the same for a week, and then getting paid, you might want to email support.
They do seem to pay a LOT some days then, some days not so much... see my stats:
https://a-ads.com/ad_units/7749/statsYou can get stats from any site that has an a-ads banner, just get their ad number from their banner and put it in the url, not so anonymous...lol
Payment proof for a-ads:
http://bitcoinwork.info/bitcoin-payment-proof.html#a-ads