I can't seem to find this mentioned on this forum? Lots on how long it takes for funds to get to mtgox, but nothing on how long it takes for a buy command to show up in My open orders, or be completed.
I did see a forum post dated today at 11am
http://forum.bitcoin.org/index.php?topic=15721.0 mention that a bug in mysql was causing the whole trading system to lock up. Is that what is causing the problem?
ALSO: What happens if you try and buy as many Bitcoins as possible, but forget to allow for the 0.65% trade cost? Will mtgox simply try and buy as many as you have money for?
