There was a problem with the Color Star Exchange where it was possible to exchange color stars for the same Creator's Room theme multiple times. We have now corrected this error and have returned color stars to the accounts of all users who were affected.
Flipnote Hatena for Nintendo DSi was designed to not allow more than one exchange of color stars for Creator's Room themes that you already have. However, the Color Star Exchange on the Flipnote Hatena mobile website allowed color stars to be exchanged for the same theme more than one time.
As of today, Hatena has taken measures to ensure that this problem will not happen again and returned the color stars to users who made multiple exchanges for the same theme. Please accept our apologies for any inconvenience this situation may have caused, and thank you for your continued support of Hatena's online services.