I personally would just be happy that you have a discover card ... at this time it seems that ALL credit card companies are tightening up policies and models.
I talked at length to a credit analyst at discover and she told me that discovers new rules include no one will be issued a Discover card over 16,000 limit ... I had a 25,000 limit and she said it would have been lowered accordingly at sometime as they had made a corporate decision to review accounts and cut back on their exposure. Keep in mind I have a few cards in the 20k range but they chose to cut the limit to 11,500 after being at 25k for quite awhile, basically since I have owned the card.
Do not tempt them to look at your credit .. just relax and keep up the good work rebuilding the credit and keep your balances super low ..they did not like the fact that i took advantage of a balance transfer and had about a 40% util on their card that would have been paid off in 60 days but now i will just leave the balance as i think they will chase the balance just like AMEX has done to most people that had a cld.
