No Task Switching in FreeRTOS

Hi…
we are working on a port of a new processor and port seems to be working fine
except that it is not switching between tasks!!!!.The higher priority task keeps on running
again without switching to lower priority task. can anyone one give us a clue as what to change or what to look for
i guess we need to configure FreeRTOS rightly in FreeRTOSConfig.h
but please suggest some solution for it as solution.

No Task Switching in FreeRTOS

we are working on a port of a new processor
A new processor?  Or an existing processor that is just not yet supported?  Which processor is it.
seems to be working fine except that it is not switching between tasks!!!!
Um.  In which way is it working fine then?  ;o)

No Task Switching in FreeRTOS

we are working on an existing processor(MPC5554) that is  not supported yet.
we got an unsupported port from richard barry that was supposed to be
compatible with MPC55XX.we might need to add some changes.
well its quite a relief when the debugger doesnt stuck at various places within
OS source code but the real requirement is to switch between tasks.