or is there someone I can send my wallet.dat to take a look at it?
Of course, in doing so you are trusting the person that you send it to with your bitcoins in the wallet so keep that in mind.
It is possible the problem is not with the wallet.dat but with some other file.
Firstly, make sure you have a back up of your wallet.dat
To determine if the problem is with the wallet or somewhere else, do you have another computer that you can put bitcoin 0.52 on and copy your wallet there? Or else you could on your current system clear out the data, and reinstall the client, restore the wallet.dat file and see if the problem persists. A recent blockchain copy is available here: http://eu1.bitcoincharts.com/blockchain/
(though know that there is a risk to using a blockchain obtained from third-party source)