I use to be a supporter, and I had a res on the utopia server i believe( at least my names still on the res list) and i think its making it so i'm unable to claim a new res? I tried / res reset among other commands and no luck.
Hey mate, you still currently have an active lot on utopia. Even though your utopia lot is your 'bonus' lot it still counts towards your lot count. To claim a new lot i believe you have to unclaim your utopia lot, which will bring your lot count to 0 and allow you to claim a smp lot again.
Shaun is correct, you will need to unclaim your Utopia lot using /res unclaim , we need to come up with a policy to take away Utopia lots from people that fall out of supporter status