I've had 2 problems with DataObjectManager and wanted to make sure they hadn't been dealt with before making a bug report.
I described my setup and attached my classes in this thread - http://silverstripe.org/general-questions/show/267361
1. I associate products with a particular page by clicking their check boxes and then clicking 'save and publish'. This enters the association into the correct database table and all of the files show up on the front of the site like they should. The problem is that when I leave that page in the cms and then come back none of the dataobjects are checked and if I click 'save and publish' all of those now unchecked dataobjects are disassociated with that page removing them from the database table and the front of the site.
2. When I try to search my list of dataobjets it starts searching before I have finished typing and then refreshes the search field with an incomplete query, even if I had typed more after it started but before the refresh. I can't enter more than 4 or 5 characters before the auto search starts.
Edit - Dio5 on IRC just pointed me to http://open.silverstripe.com/ticket/4250 and I'm about to upgrade my local version of the module from r244 to r253
you can change the 200 to a different value. Just understand that if it's anything other than 500, you'll have to reapply the change it every time a new version comes out. :)