On September 10, 2014 Vanguard upgraded their system. This upgrade has affected downloading for Vanguard accounts in iBank. We have identified the issue and plan on having iBank updated to match with Vanguards new system on Monday, September 15, 2014.
On or after September 15th you will need to disable downloading for your Vanguard account in iBank, then set up downloading again.
In the meantime you should be able to update your account manually by downloading/importing files from Vanguard into iBank. iBank can import OFX (MS Money), QFX (Quicken Web Connect), or QIF (Quicken) files for investment accounts.