When I bought Shade 7 from CL's DigitalRiver store I had problems like this. Their customer service person advised that if I got an error message about serial numbers or credit card problems during my order, I needed to wait 24 hours before attempting to place the order again. It's apparently due to the draconian security measures they use to validate orders. Eventually I got it to take my order and I'm now a happy Shade user. So for those of you trying several times per day with no luck, I suggest waiting 24 hours before you try again. I must say I haven't experienced such annoying behaviour with any other online store, and like the earlier poster I agree it seems you have to practically beg them to take your money. But be patient and your order should eventually go through.