Not sure if this is a plantuml or graphviz bug but since i've updated graphviz from 2.38 to 2.40.1 the relation lines drawn between two classes within a namespace are rendered way too long when I add a label to the relation.
Example (See output here: http://imgur.com/a/UIQXW):
@startuml
namespace Vehicles {
Toyota --|> Car : implements
}
@enduml
This issue doesn't happen when used in the online plantuml editor but I'm not sure which graphviz executable is used here