Groovy 1.5.2 made it so fast into the hand of end users that they were able to provide quick feedback on some regressions that sneaked under the radar, that is why the Groovy team and G2One, honoring the commitment to high quality software, have released Groovy 1.5.3 (JIRA report).
Please take a moment to upgrade if you haven't done so, the installers should be up in a couple of days too.

Keep on Groovying!