Be sure that you have the latest monero wallet from the main thread.
Do a backup (copy) of the 3 wallet files in a separate folder.
Go back to your main monero folder and delete the wallet.bin file (keep the 2 others).
Launch the wallet program. It will reload all transactions since the start.

If your XMR doesn't appear at this point, send me a PM with the exact amount of missing XMR and your address.