Okay, both transactions now show up on blockexplorer!  I guess I just didn't leave the client running long enough.  Now I just have to wait for confirmations, I suppose...

Thanks, everyone! 

I already have the block chain.  Could the fact that I've used more than one wallet with the same block chain be what's causing my problems?

Well, I'm less of a computer newbie and more of a bitcoin newbie, so if you'd like to explain the process to me, I'd be grateful.

One more thing I forgot to mention earlier: these were both sent without transaction fees.  Hopefully there shouldn't be THAT much of an impact because of that, though?

I'll leave it running and see what happens.  Thanks.

Hello all,

I'm having a little problem, and I was hoping someone more knowledgeable might be able to give me a hand with it.  See, a while back, I bought some bitcoins (some for myself, some for two friends - we'll call them A and B) and had them sent to my address.

I have a Mac, and keep my wallet on an encrypted portion of my HD as recommended on the bitcoin wiki.  Because writing to the encrypted part is extremely slow, I had to download the blockchain manually and put the file in there and then start with -rescan.  Then I was able to see the bitcoins that had been sent to me, and all was well for a time.

Since then, I have renamed the wallet.dat in order to force my client to generate a new wallet file for me to use.  I needed two wallets because I wanted to keep A's bitcoins in a separate place from mine (he's asked me to hold on to them for a bit), but when I tried to send the bitcoins to the wallet I'd created for him (essentially, sending them to myself) it listed my transaction as 0/unconfirmed.  It's been almost two months, and that hasn't changed.  Looking at block explorer, the transaction never seems to have gotten into the block chain - but the balance on my computer includes the credit for the "sent" bitcoins.
Then, more recently, B asked me for his bitcoins, and I tried to send them to the address he gave me.  It also listed that transaction as 0/unconfirmed, and that transaction also doesn't show up in block explorer... and it's been about two weeks since I sent it.  So, the money isn't with them, or even in the blockchain... but it's also not with me.  I don't know how to persuade my wallet that the transaction it sent should be undone, either.

I have a backup of my wallet file from before I sent B's transaction, but not before I sent A's, and loading that backup shows my transaction history as it was before I ever sent to B.  This is good, but it sounds like I'd also need a backup from before I sent to A in order to recover all the bitcoins.

So I come to you, wise forum, for help.  How do I recover the bitcoins that are neither here nor there?  And if it's not too much to ask, why might the bitcoins I send get stuck?  Thank you!