EA ran into two separate, yet equally important, serial key problems with the release of Red Alert 3. The first issue was that the serial key pinged back as being "invalid," while the other involved a missing digit in the 20-digit code. Here are the solutions from the EA site:
Invalid key issue: EA says the issue should be resolved by now. It involved a "small amount" of keys not being pre-loaded to the company's "backend." Coincidentally, the same place where customers probably felt like they were kicked.
Manual has 19 digits instead of 20: Either click here to contact customer service, or resolve the issue by trial and error. The only thing missing is the last digit, which is either "a number from 0 - 9 or a letter from A - Z." That leaves only 36 possibilities.
EA apologizes for the inconvenience. In Soviet Russia, inconvenience apologizes to EA!