Today I added the latest version of Mambo, version 4.5.2.1, to the filebase here at Mamboportal.com. According to the Development Team the version is fully backward compatible with Mambo 4.5.1. So you should have no problems running existing 4.5.1 CMT's on this version. The new 4.5.2.1 release is mainly a bugfixed version, which does not introduce much new features:

• Menu will be hidden, when you edit/add content items. (Personally I find this one more disturbing than usefull. It's not a bug, it's a feature... :-)
• Solar Flare II has been added as new standard template
• The help system has been reworked. It has been cleaned up, finally supports html help files and 3rd party developers now can at help text to their CMT's.
• Some smaller changes have been made at the build in component's and module's like Contact now supports V-Card download and an email cloaking Mambot has been added (thumbs up for this badly needed feature!).