weird data-grid-view/crystal-reports behaviour c# winforms

Question

I have a winforms project which I keep in different versions, each version having its own project folder. All these projects use the same database file, which is copied in each project folder too.

So if I run a project, let's say 0.34, and then I try to run 0.35, all the database functions don't work, unless I detach the database in SQL server management studio express. So all the database functions don't work, except the data grid view and/or crystal reports.

But then, if I detach the database, and I run any version, all the database functions work, except the data grid view and/or crystal reports.

So to recap, when the database functions work (like select), crystal reports doesn't work. But when the database functions don't work because the database is not detached, crystal reports works.

weird. any ideas?