Looks like the xsd has errors as per the w3 xsd validator. I tried to verify it at http://www.w3.org/2001/03/webdata/xsv and see the error 
Schema representation errors

Detected during instance validation

http://repo.akka.io/akka-1.3.1.xsd:192:3: Invalid: non-deterministic content model for type untyped-actor-type: {http://akka.io/schema/akka}:dispatcher/{http://akka.io/schema/akka}:dispatcher

http://repo.akka.io/akka-1.3.1.xsd:132:3: Invalid: non-deterministic content model for type typed-actor-type: {http://akka.io/schema/akka}:dispatcher/{http://akka.io/schema/akka}:dispatcher

You can see the error at
http://www.w3.org/2001/03/webdata/xsv?docAddrs=http%3A%2F%2Frepo.akka.io%2Fakka-1.3.1.xsd&warnings=on&independent=on&style=xsl#

The problem seems to be declarations like:

   <xsd:sequence>
      <xsd:element name="remote" type="remote-type" minOccurs="0" maxOccurs="1"/>
      <xsd:element name="dispatcher" type="dispatcher-type" minOccurs="0" maxOccurs="1"/>
      <xsd:element ref="dispatcher" minOccurs="0" maxOccurs="1"/>
      <xsd:element ref="beans:property" minOccurs="0" maxOccurs="unbounded"/>
    </xsd:sequence>

Where the ref="dispatcher" refers to:

  <xsd:element name="dispatcher" type="dispatcher-type"/>

So basically (I think) the two "dispatcher" declarations in the sequence are equivalent. The validator's complaining that it doesn't know which one it should pick when parsing.

The fix is probably just to eliminate one of the equivalent element declarations from the sequence declaration.