LarenC has started an article on the Technet Wiki that collects usage tips and troubleshooting for Sync Framework. This can be the first place you look when you have a nagging question that isn’t answered anywhere else.
Checking this out may save you some time: http://social.technet.microsoft.com/wiki/contents/articles/sync-framework-tips-and-troubleshooting.aspx
JuneT's idle thoughts 
Good morning,
How can we do filtering for the rows that one local database should synchro dynamically? (for having only the rows that this local database has permissions to have (this data could change in time, more permissions, less permisssions…)
I would like to have in local database a subset of the data but this can subset can change in time… (dinamically).
Thank you very much!
you can specify a filter column and filter clause for both offline and collaboration providers. check out the documentation and you’ll find samples how to do it. the collaboration providers doesnt support specifying dynamic filter values though. the filter value is part of the scope definition.