users can not edit an issue which is not assigned to them
In current version(I am using v1.0.3 now), it seems that every user can edit an issue even if it is assigned to him. I am not sure is it a benefit of Redmine or just a missing. In my opinion, it should be limited the edit function of issues that only the user who is assigned to the issue can edit it, or if the issue is not assigned to anyone, it can be edited by everyone, shouldn't it?
Therefore, it is better to add an option in the Administration->Workflow which allows user to choose whether or not the limitation is enable for a certain workflow.