Having a sqlite database where a column contains guids stored as blobs.
In the select clause of a linq query, ToString() is applied on the Guid property of the model object. NHibernate will forward this to the SQL as
cast(Id as char) as col_2_0_
Unfortunately, the resulting strings won't contain the intended standard string representations of GUID, but instead the raw bytes directly interpreted as characters, which is something completely different.