Cannot import Maven dependencies anymore

Hi,
since today I can't compile any Java project in IntelliJ 12.1.4 (Mac OS X 10.8.2); that's due to the fact that I can't import Maven dependencies anymore

The only big change I did yesterday was to upgrade my JDK to 1.7.0_25. Now any project I try to build, it can't import Maven dependencies.
I tried with Maven > Reimport and by enabling auto-import, with no success.

Any help to understand what might be wrong?

Thanks,
--
Filippo