Range restriction issue with XSV

I've just done some testing, and it seems that an old bug using xs:redefine to restrict the occurrence range of a group from 1-to-many to exactly 2 is still plaguing XSV. (See http://lists.w3.org/Archives/Public/xmlschema-dev/2005Feb/0041.html, noting that the message is different.)

in http://www.ruleml.org/temp/xsv-bug/restriction.xsd:
Atom :: slot*, ( arg+, slot )?

in http://www.ruleml.org/temp/xsv-bug/restriction2.xsd:
Atom :: slot*, ( arg, arg, slot )?

XSV reports slot/slot non-determinism (pasted below) when validating http://www.ruleml.org/temp/xsv-bug/restriction.xml (which points to restriction2.xsd). If this file is changed to point to restriction.xsd, all is well.

Is this a known issue (or am I missing something)?

Dave

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Detected during instance validation

http://www.ruleml.org/temp/xsv-bug/restriction.xsd:22:2: Invalid: non-deterministic content model for type Atom.type: {http://www.ruleml.org/0.91/xsd}:slot/{http://www.ruleml.org/0.91/xsd}:slot