My appliaction is running ok with seam 2.0.x version but when I try to upgrade to 2.1.x, application becomes very slow. There is no any exception, only CPU goes to 100%. What should I do?
Attach a profiler so you can see where it is spending all its time. I use yourkit, which has a free trial, but there are plenty of them out there.
Also, did you update your schema references in pages.xml to point to the 2.1 schema?