Just wanted to give a quick thanks to everybody who tried to provide me with assistance in this thread: it's much appreciated guys.

Unfortunately at this point I would have to conclude that I've lost the money. I no longer have the private key for the transaction and I foolishly neglected to back up my wallet. Guess that's one for the lessons learned file!

Anyway, thanks once again fellas.

Thanks for the advice.

The address I provided and which the funds were sent to was: 1L1T35UsuL63acp93HszTMi5xbzgizu6az

A check on blockchain.info shows that the transaction did indeed go through to this address! So that's something to start with I suppose...

Alas, the above rescan option has been to no avail.    I've upgraded to the latest version of Bitcoin Core and tried again, but still no joy  .

Any other tips you could kindly offer?

Thanks for that mate. I'll give it a try and fingers crossed it will sort out my issue!

I'm afraid I've done something very dumb through ignorance and panic and lost myself some bitcoins. The question is whether the process is somehow reversible and whether I can somehow get them back. Any help that anybody could provide me with would be much appreciated. Let's take it through step by step:

The other day I was browsing some, ummm.... "exotic" material on the internet.

While browsing I was suddenly hit with a locked, obviously fake "MSN" screen informing me that my PC was being "encrypted" and that I would need to call such and such a number to sort it out. I quickly hit the power off button. Then rebooted. Everything appeared OK and a full security check failed to turn up any issues. So far so good.

The problem was I'd stupidly left my bitcoin core wallet open to receive a transaction while browsing. I didn't shut down the wallet properly before resetting my computer. So when I loaded the wallet back up, the block chain appeared to be out of sync and started rebuilding itself. This wasn't such a problem, but rather worryingly, I noticed that the amount pending in my wallet had been reduced by roughly one half. I wasn't sure if this was something to do with the chain rebuilding itself, or if thieves had somehow managed to dip into my wallet (sorry if I sound really ignorant here - I don't know how likely or possible this is).

I decided to let the block rebuild itself and see where I stood. The problem is, when I checked back later, the amount pending was dropping further as the block rebuilt. At this point I started to panic and thought that perhaps thieves were having an open season on my wallet.

Out of a sense of desperation (and I really don't know whether this was a sensible thing to do or not) I hit the "reset options" button under the options section of the settings menu. This had the effect of unencrypting my wallet and basically starting from scratch. All my previous transaction history disappeared, all values were set to zero and the block had to rebuild itself from the start. This made me very frightened that I'd done an incredibly stupid thing.

Not knowing what else to do, I just let the index rebuild itself in the hopes that my bitcoins would reappear. But at the end of the rebuild (over a process of several days) the total value available to me remained at zero.

I really don't know what has happened at this point. Whether I have been robbed blind or whether I've messed up myself here by hitting the "rest options" button.

The question is, is there any cure for my ignorance and stupidity? Can I find out what has happened? Any way to get my precious coins back? Somebody please save me from my complete and utter dumbassery.