Since Patch 4.0.1 there are some Bugs with the raid lockout system. TotC10/25 and Ulduar10/25 reset everyday.
We went TotC25 and Ulduar25 two days ago on patchday, the people try to configure their interfaces and so on, we cleared it completely.
Yesterday I went to Ulduar25 again and the instance was reset, so we cleared it again.
And today I check my "Raid Info", ID still there but Ulduar25 is completely reset and we're going to clear it again.
Everyday a Mimiron's Head if you're killing yogg-saron alone. ;-)
I play on a german (eu) server.
Sorry for my bad english.