Can schemas be in the default namespace?

Is it legal to do this?
  <schema xmlns="http://www.w3.org/2001/XMLSchema">
    ...
  </schema>

I'm dealing with some schemas that don't use a namspace prefix for the
schema namespace, ie. they are defined like this:
 <schema xmlns:xsd="http://www.w3.org/2001/XMLSchema.xsd" xmlns="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">

Ie. they have set xmlns="http://www.w3.org/2001/XMLSchema" (and
xmlns:xsd="http://www.w3.org/2001/XMLSchema.xsd" as well, though the
"xsd:" prefix isn't used anywhere I could see).

XML Validator Buddy[1] didn't complain about this, but eclipse WTP[2]
(WTP 3.6.3 on Luna SR2) on
 <import namespace="http://www.myorg.no/xmlstds" schemaLocation="../common/myorg.xsd"/>
gives the following error message
 schema_reference.4: Failed to read schema document '../common/myorg.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not <xsd:schema>.	ER-M30-2014-12-01.xsd	/MYProject/Myfolder	line 13	XML Schema Problem

The XSLT-based XSD to RNG converter[3] says:
 error on line 11 at column 37: xml namespace URI cannot be the default namespace

Who are right?  Is it possible to tickle the schemas so that WTP and/or
the XSLT converter will accept them?

Is the problem that both the outer schema and the imported schema uses "xmlns="?

Thanks!


- Steinar

[1] http://www.xml-buddy.com/ValidatorBuddy.htm
[2] http://www.eclipse.org/webtools/phoenix/webtools/
[3] http://debeissat.nicolas.free.fr/XSDtoRNG.php