Actually have tracked it down to a specific project.
Added:
ButtonPanel1: TButtonPanel;
DataSource1: TDataSource;
DataSource2: TDataSource;
DBEdit1: TDBEdit;
DBEdit2: TDBEdit;
DBGrid1: TDBGrid;
DBNavigator1: TDBNavigator;
Label1: TLabel;
Label2: TLabel;
MainPanel: TPanel;
MemDataset1: TMemDataset;
Panel1: TPanel;
SQLite3Connection1: TSQLite3Connection;
SQLQuery1: TSQLQuery;
SQLTransaction1: TSQLTransaction;
Linked those up to a SQLite3 DB (I have 3 forms that are COPY-N-PASTE clones of the above)... when I run the App, click on the DB Navigator, or a different row on the grid - things appeared frozen, then I get a Stack Overflow error... run in DEBUG mode (windows64) I get Project raised exception class 'External: SIGSEGV'. At address 100223C16.