cracked windage tray in sump

Has anyone suffered cracks in the tray? This is the 2nd time I've had to get them welded up. This time the forward part has broken loose, not just cracked!
What causes this? It is in a road going Mk2 RS2000, not a racer.
What causes this? It is in a road going Mk2 RS2000, not a racer.