On a few occasions I have noticed that after placing some components in Router, these same components come up with a clearance violation error when running the design verification check in Layout. DRC clearance does appear to be correctly enabled in Router as it does prevent me from placing components very near to each other as an example. Does Router and Layout use different rules or some kind of offset? I have DRC and "Clearance" in prevent mode enabled in Router.
I am using Pads vX.0.
I have seen this many times as well. Typically for component placement.
In my opinion it is a bug. Both layout programs must of course report the same clearance issues.
I have reported this issue to Mentor lots of times, but so far it has not been fixed.