Earlier this month we posted Update to JBoss Tools 4.1 and Developer Studio 7.0 which was done to remedy some of the issues around a regression bug the _40 update to Java caused to Eclipse and hence our tools.
Last week Oracle released _45 update for Java 7 which fixes this issue and you should now be able to do updates and installs reliably again in Eclipse based tools.
Thanks to Oracle for the quick turnaround!