Index: maven-artifact-manager/src/main/java/org/apache/maven/artifact/resolver/DefaultArtifactResolver.java
===================================================================
--- maven-artifact-manager/src/main/java/org/apache/maven/artifact/resolver/DefaultArtifactResolver.java	(revision 706694)
+++ maven-artifact-manager/src/main/java/org/apache/maven/artifact/resolver/DefaultArtifactResolver.java	(working copy)
@@ -157,7 +157,7 @@
 
             // TODO: would prefer the snapshot transformation took care of this. Maybe we need a "shouldresolve" flag.
             if ( artifact.isSnapshot() && artifact.getBaseVersion().equals( artifact.getVersion() ) &&
-                destination.exists() && !localCopy )
+                destination.exists() && !localCopy && wagonManager.isOnline() )
             {
                 Date comparisonDate = new Date( destination.lastModified() );