maven.vaadin.com isn’t browsable, but Maven should be able to download add-ons from there just fine as it knows the path for the add-on based on the group id, artifact id and version.
As I said before, i can’t download via maven. Here is output. About month ago, maven worked like a harm.
09-Jan-2014 15:30:27 [ERROR]
Failed to execute goal on project Project: Could not resolve dependencies for project com.sean:project:war:0.1: Failed to collect dependencies at net.sf.jasperreports:jasperreports:jar:5.5.0 -> com.lowagie:itext:jar:2.1.7.js2: Failed to read artifact descriptor for com.lowagie:itext:jar:2.1.7.js2: Could not transfer artifact com.lowagie:itext:pom:2.1.7.js2 from/to vaadin-addons (http://maven.vaadin.com/vaadin-addons): Connection to http://maven.vaadin.com refused: Connection refused: connect -> [Help 1]
The last part of the error message comes from a transitive dependency that probably should be in Maven Central - not a Vaadin add-on. Normally Maven just tries to contact all the configured repositories until an artifact is found, and gives an error message for repositories where in which it was not found (even if it is later found in another repository) so that part of the message is normal. The beginning (if not cut out of context) does suggest, though, that perhaps Maven is not checking Maven Central for that artifact at all (configured that way at your end or not found in central and that resolution cached?).
If something is not working, some additional information is probably needed about the problem and the project configuration and what Maven outputs.