Looking at docs for older version (Weld 1), I can see following:

That means each archive that contains beans must include a file named beans.xml in the META-INF directory of the classpath or WEB-INF directory of the web root (for war archives).

So I am quite surprised that it worked for you before on Tomcat 7 with Weld 1 under META-INF.

When you are deploying via IDE, what does the deployment look like? It is an actual WAR at all?