By default DevForce does use DBCC CheckIdent when working with Identity keys. You can instead use a DevForce-supplied stored procedure to handle Identity keys - this requires installing the stored procedure and settting an option in the config file. You can find a step-by-step description of how to set this up in the "Sql Server Identity Id Generation" section of the Developer's Guide.
I should add that you do have another option for key generation. A common means of handling Id generation in DevForce Classic is to implement an IIdGenerator. This may sound harder than it is, since you can generally use the "NumericIdGenerator" class found in many of the learning units as is.