The Sqlite32/64 projects were missing the override of ExpressionVisitor. It's a pretty nasty bug. I added a fix for this to my Pull Request.
However, it's a fundamental failing of the copy-paste scenario we've got going on with the three Sqlite implementations. All three of them should reference the same code aside from the one method that's different in each. I'm okay if this is done through the "Add as Link" ability (assuming we don't want to seriously consider a single Sqlite implementation where the user is forced to specify/load the platform-specific dependency). And of course tests should exist for as much functionality as possible, including the LINQ support.
What was the purpose of supporting both System.Data.SQLite and Mono.Data.SQLite ?
Also, the SLN changes in my pull request were just add back the few projects that weren't selected in the build configuration (both debug and release). I don't know why they weren't selected as they build fine...