[Setup] Problem with Workflow/WorkingCopy

[Salami738]

version information:
Plone 3.0.0-3.1.1
plone.app.iterate 1.0-1.1.0 (working copy support)

my problem (traceable on a blank Plone site, installed "Working Copy 
Support" via control-panel):
I have a user who can add documents to my site. I don't want to trust 
him so much, that i am willing to give him the "publish" right.
All items must go throught the review cycle, and he isn't allowed to 
modify published documents. Now i need working copy support, to check 
out the document, review it an publish the new version. Until then i 
want the old version online.
The problem is, that he can't check out documents without the 
"modify_portal_contents" right.
The problem is open in the issue tracker 
(http://plone.org/products/iterate/issues/24)
Any suggestions?

regards,
Benjamin Bauer