So, we uploaded the managed package and installed it in a new org (as the clients would) but when accessing a vf page we get the error

SObject row was retrieved via SOQL without querying the requested field: namespace_MyObject_c.namespace_CustomField_c
The problem is that on the previous org everything works fine and on that VF Page we are not actually referencing any value that was the result of a query.

Any idea why this is happening?  We checked the namespace but when we changed it in the development org, it gave us an error.