CardArcade's Network Ranking feature does not appear to be working properly. As a result, scoreboards are limited to local scores for now. I am working to address this issue as quickly as possible! Gameplay is unaffected. Feel free to improve your scores, as they will sync properly once the feature is fixed.
Please understand that once a fix is submitted, it may take up to 2 weeks for the new version to actually be approved by peer reviewers. I will post here once the fix is in review.
I apologize for this... if anyone feels cheated because they did not get a feature they paid for, please PM me and I'll make things right.
EDIT 8/22: I'm almost there with the Network Ranking feature...not only does it now work, but I've improved it by using multithreading, avoiding the hiccup in gameplay it was causing before (you may have noticed it). I'm just fine-tuning...it should be done for good within a few more days.
EDIT 9/2: Version 1.1 of CardArcade has been submitted for Peer Review on XNA Creators' Club. Once approved, the new version will be available to everyone. I will post again when this has taken place. The process may take up to two weeks, but I'll do everything I can to try to move it along.
EDIT 9/19: CardArcade version 1.1 is now available! This version fixes Network Ranking, and adds other minor fixes and enhancements. The game should not crash while Network Ranking is enabled, but if you are unlucky and experience a problem, try turning the feature off by choosing "Network Ranking Opt-Out" in the Game Options menu. Thank you for your patience.