In order to insert SetCurrentLocation and CheckSessionExpiration into the servlet pipeline, they must start at the same time as the Oracle Commerce Core Platform. To accomplish this, we added the following lines to the /atg/dynamo/servlet/Initial component:

initialServices+=/atg/projects/b2bstore/servlet/SetCurrentLocation,\
             /atg/projects/b2bstore/servlet/CheckSessionExpiration

These servlets are located in <ATG11dir>/Motorprise/src/Java/atg/projects/b2bstore/servlet/.