I believe what you guys are saying, and I'm maintaining my cautiously optimistic outlook, but the reality is that I've done everything suggested and I still show "no block source available" and show a zero balance.  It's been a week since the problem first occurred.

I'm thinking I'd like to reinstall.  What's the best way to uninstall before a reinstall?

There are multiple nodes showing with ping times all between 101 and 135 ms

I don't see how it could be a firewall issue.  I've been running Bitcoin-Qt for years with no problem from this same iMac.

How do I navigate to the "debug console"?  I don't see it.

I just upgraded the client to the current version, but I'm stuck with "No block source available..." for about the last hour.

Can you expand on your instructions a bit?  I don't know how to import a wallet and I'm not familiar with getpeerinfo or addnode?  Thanks so much.  I'm missing a significant number of coins at this point.

So I forced a shutdown on my mac running 10.10.4 Yosemite, and when I restarted Bitcoin-Qt v0.8.4 I get:

"System Error: Database Corrupted". I then click OK, and the program "quits unexpectedly"

After googling a bit, I find what seems to be a simple fix.  I goto /library/application support/bitcoin/blocks
renamed the "index" folder to "index1", and restarted bitcoin-qt.

This seems to help.  The program opens without the error message and begins reindexing.  It shows a balance of 0 BTC, but an unconfirmed balance equal to my original balance.

However, now I see the message "Warning displayed transactions may not be correct, you may need to upgrade or other nodes may need to upgrade".  I let it sit for 5 days straight and nothing changes.  It still reads "synchronizing with network" across the bottom, but the status bar hasn't moved.

Now I'm getting worried.

I quit the program, copy my wallet.dat file to the desktop and run this code in terminal:

open /Applications/Bitcoin-Qt.app --args -salvagewallet

Now everything is the same, but even my UNCONFIRMED balance shows as zero!

Any help would be appreciated.  I never thought bitcoin was this fragile.

I got the green check, and the transfers showed up!  Thanks for all of your help.

Thanks!  I dont see the green check yet..  it's rotating yellow circle!  How long does it take to fully download?

It's scaring me that Mt. Gox shows the withdrawal, but I don't see the deposit in the Bitcoin-Qt app.