Posted this to reddit, but hopefully I'll get more of a response here...
I've been trying to send a transaction via Mist to The DAO. I run both a stand alone geth node installed via homebrew and Mist.
When I first start the geth node, it begins syncing ok, but when it catches up to the highestBlock it fails to download any more blocks for a while. Eventually it will download a couple hundred blocks at once, but it's like it pauses in between downloading. eth.syncing returns false, and eth.blockNumber always returns the same block height as when it first launched. Quitting and reopening will cause it to start syncing again, but only up to the highestBlock recorded when the app launches.
If I try just using Mist, the embedded geth node seems to act the same way. Syncs up to the highest block it sees on launch then pauses and as of right now it says "an hour since last block".
Attempts to send transactions from mist always fail. The dialog disappears after hitting send, but the Ether doesn't send and the send button says "sending...". http://imgur.com/QyrBuJ4
When I quit Mist, a notification briefly appears saying the send transaction timed out.
Geth is also reading/writing a ton of data. I left it running over night to see if sending ether would work this morning. I checked the activity monitor this morning and Geth has written over 75GB and read over 107GB from the hard drive in the last 12 hours or so... Is that normal? it seems kind of excessive for a 16GB blockchain!!
Mac OS X 10.11.4 Geth 1.3.6 Mist 0.7.2