As the error message states,your connection pool is full. YOu can either:
1. Increase the pool size, but I guess this will just solve the problem short-term :)
2. Do not use connection pool (not a good option)
3. See if you somehow leave connections open and don´t close it explicitly (which should be done within the scope thei are opened) Normally the garbage collector should and collect open connections, as far as I remember this is defined in the IDisposable Interface, but doing that explicitly will let you sleep better :)