Once you click the confirmation link(e) in the email, you would be redirected to a new page in your browser notifying you that your withdrawal confirmation has been successful as shown in image below.
In your withdrawal history section on the wallets page, you would notice the following: When you click the plus sign; you would notice the address to which TheDAO tokens were sent and TxID for the transaction which you can enter into the search box on www.etherscan.io to further verify that the transaction was successful.
Incomplete withdrawal address(missing letters or numbers) entered during 2. above. You would only notice this error after 5. above, whereby in the pending withdrawal section, you would see under status that the transaction was either Invalid or another error message. Solution: Click cancel and try the transaction again. No fee would be deducted when the error DOES not result in a transaction.
Send to deposit address denied: You might notice this during 2. when you enter the same address as your deposit address and click confirm. You would see the following image below: Now in this instance, it was quite weird as the Bittrex platform threw an objection to requesting a withdrawal to the same address that was used to deposit the tokens.
Solution: Cancel the request and enter an address different from your withdrawal address or enter in your deposit address again and click confirm. The second time I entered in the same deposit address during 2. above, it did not bring up an error message and the transaction completed perfectly.
Incorrect withdrawal address: You would only notice this after a successful transaction.