received block 00000000000000059a79f3ca43ec398f5e47d36c4257aadf8de7711ce375c2bd
InvalidChainFound: invalid block=00000000000000059a79f3ca43ec398f5e47d36c4257aadf8de7711ce375c2bd height=273050 log2_work=74.487248 date=2013-12-04 16:27:28
InvalidChainFound: current best=000000000000006b466577ecb823f117f86f77ef22a8eefa78d138ecbda6e890 height=198855 log2_work=68.701384 date=2012-09-15 08:05:19
InvalidChainFound: Warning: Displayed transactions may not be correct! You may need to upgrade, or other nodes may need to upgrade.
ProcessBlock: ACCEPTED
I suspect that you don't have the latest version of Bitcoin-Qt, and/or the blockchain you have already downloaded is corrupted or invalid.
The 'orphan' messages in your logs are normal for an out-of-sync Bitcoin, those are "live" transactions broadcast from other Bitcoin users, using funds that haven't been seen in the blockchain that you have downloaded yet.
The "current best" is the last block that your client has downloaded and recognized as valid. The 273050 "invalid chain" block is the most recent real block that was broadcast to your client when it was found; bitcoin doesn't know what to do with that because it doesn't have the required previous blocks.
The solution to your problem is going to be as I described above:
1. Get one of the linked 0.8.5 test builds that should solve the frequent OSX corruption problem in recent Bitcoin-Qt versions,
2. In the bitcoin data directory, remove the blockchain you've downloaded so far, by deleting the "blocks" and "chainstate" subdirectories,
3. Optional: for faster initialization, get the
bootstrap.dat torrent and put this in your data directory before starting bitcoin (instructions:
https://bitcointalk.org/index.php?topic=51456.0),
4. Start Bitcoin and patiently download blocks again.