My shopping page vanished after installing PPal??

Hello wise one's.

I am not 100% sure if I am posting this in the correct section but I am completly new to this so go easy on me.

I wonder if anyone could help me with some information and advice as to why after installing Paypal Express - my shopping cart page completley vanished making my eshop useless.
I am sure it was something that I have done as I only installed Paypal AFTER i failed to install google checkout so I may have done something then which later had the current effect - ie No shopping cart.
I am at a loss as to where to begin but here are some details.
I am using Twist of Nature Template and I am hosting through dreamhost.
I have left the code part as is apart from when I tried to run google checkout - I don't know what else to put.

I have been looking for an answer but like I say I am new to all this so if anyone has any suggestions on how to fix this problem or if this as ever happened to someone else then please let me know.
Thank you in advance for any help you can offer.

P.S. I have just noticed that when I went to my zencart admin to the define pages editor my cart is no longer an option - what is going on?

Assuming you're using Zencart version 1.3.9, look in your /cache folder for error logs which may give you an idea about what's gone wrong. I'd suspect the GC files.

I see what I did wrong now and I have fixed the problem. It was the GC files as you suggested. I had left something where it was not suppose to be.
Thanks for your help.