I'm getting these too:
12:45:53.322952 INFO ----- BLOCK ADDED AS ALTERNATIVE ON HEIGHT 29101
12:45:53.322952 INFO id: <8a8d81a0bbe6ed7514f4aaccdedfa5461d4851fee1f901849d178e2f1473528b>
12:45:53.322952 INFO PoW: <6ef45f6fdca33e0d11f2a90ec8fa4fc30bc2f55a7d8b31356937d4731efb0000>
12:45:53.322952 INFO difficulty: 23418
12:45:53.402943 INFO [163.172.37.154:47767 OUT] SYNCHRONIZED OK
12:45:53.815050 WARNING [163.172.37.154:47767 OUT] Exception in connectionHandler: TcpConnection::read
My pool seems to be in sync if I compare the mined block height with the other pool
Using pre update daemon & wallet
This is somebody with daemon v1.1 who needs resync or run v1.2, then these blocks will be discarded.
Important: Bug was discovered in reset feature in simplewallet v1.2. For some reason it resyncs only since last alternate chain known by daemon (height 29059). If you don't see coins you received earlier, the easiest way is to stop daemon v1.2, start simplewallet v1.1, reset (reset was there already), close wallet, backup the wallet file (it is small and you can use it instead of reset later), start daemon v1.1, wait for sync, start simplewallet 1.1, wait for the wallet to reload all txs (use reset again if it just shows prompt without reloading), check balance. Close wallet, backup wallet file again (to save its state), shut down v1.1 daemon and run v1.2 daemon and wallet.
Never run different version of simplewallet against different version of daemon, it will show nonsense balances and will not be able to sync after reset properly, throwing odd errors both in daemon and simplewallet. Even if you do so, follow the reset procedure above, your wallet keys and coins are always safe.