Winter 13 anomaly 

I have a test class Foo that among other things:

* inserts a ContentVersion

* inserts a ContentWorkspaceDoc

* updates the ContentVersion with custom field values and tags

If I login to the Winter13 sandbox using credentials for system administrator X, select class Foo and Run Tests - the tests pass fine

If I use Ecliipse IDE Version 24.0.0.201202291629 also logged in as user X and do Apex Test Runner on the very same class Foo, I get the error:

System.DmlException: Update failed. First exception on row 0 with id 068V00000008ILuIAM; first error: INSUFFICIENT_ACCESS_ON_CROSS_REFERENCE_ENTITY, insufficient access rights on cross-reference id: []

where the ID is the ID of the ContentVersion record and the DML is on the Update of the ContentVersion record

These tests all ran fine in Eclipse prior to the sandbox being upgraded to Winter 13

Here's what I don't get:

Doesn't Eclipse IDE simply instruct the sandbox cloud to execute the test class Foo, all execution occurs in the sandbox cloud, and the results/log are merely passed back to Eclipse?

Given that the Ecliipse project uses the same credentials as those I use to UI login to the Force.com platform, the Eclipse test execution should execute the same as running the test via a Force.com Run Tests button click. True?

What could be different here? Does the Winter 13 sandbox code somehow execute the test class submitted by Eclipse with different context than when I execute it from the Force.com UI?  I've never seen this before and I've been running this APEX class in Eclipse successfully since V19.0