Rate Monotonic Problems

[CARERI/SED]

Hi,
We have built rtems for target i960, and got it work on the board.
We found there is problem in the case:
	1.Define the  TICK  as 20ms.
	2.Use a rate monotonic of 2 ticks in a task to insure that the task would be completed in 40ms
   But the task consumes 53ms actually , and the rtems_rate_monotonic_period returns  "status" RTEMS_SUCCESSFUL., there are NO TIMEOUTs. 
	 And I can only explain it as following:
		Whe the rtems_rate_monotonic_period returns  the Counting-Tick is 2, though the real time is 53ms, but it has not reached 60ms (3 ticks), so it return SUCCESSFUL, and meanwhile it set the Counting-Tick to 0, and so on.

Am I wrong? and What's your explanation?

Sincerely,
Su Wenming