I guess that you mean ordering at CW's site ?
Hve done that something like 5 times now (not to mention countless occations in a bunch of other shops), never any problems.
You are quite well protected, firstly in the encryption of your payment-details, just observe that you are switched to a secure server, secondly in the protection from you creditcard company if any fraud (the shop or a hacker) occurs.
To find out more about this, there are several pages, try @ you CC company's homepage or your bank.
As long as you stay with reputable comanies I think there is no problem. I've made maybe 100 online credit card and money transfer transactions with no errors.