I recently upgraded my ZC to 1.5.7c and all seemed to be working, except....

I have been using PayPal Standard for years. When testing payments, all works well with COD or with a gift card!
When paying through PayPal, TWO Orders are generated, although there is only ONE Charge!

I did have a couple of orders the other day, and Did Not have duplicates (was still on PayPal Standard)
I had (3) orders in a row today, and all-3 were duplicated.....

I thought that it was a sign that it was time to upgrade to PayPal Express.....

BUT !!

I installed PayPal express and I'm sure that my API Credentials are correct, but when testing and I click on the "Go to Checkout" button from the shopping cart page, I get a Blank-White Page which reads "Page Isn't Working" and ERR_TOO_MANY_REDIRECTS......

I really hope someone can help!!??