When trying to truncate a table that is referenced by a Foreign Key I always get this message, even if the table referencing the primary table is empty.
Server: Msg 4712, Level 16, State 1, Line 1
Cannot truncate table 'actTouches' because it is being referenced by a FOREIGN KEY constraint.
To get around this problem I simply delete all rows from the table then re seed the identity column with 1.
Delete From [table]
DBCC CheckIdent ([table], RESEED, 1)