CM3, rtos crashes after starting a third task

Hey guys, i’ve got a question but first of all I am sorry for my bad english. Here’s the problem:
i’ve got an stm32f107vc and i would like to use freeRTOS because I have to do a few tasks in parallel. that’s my task list: Task 1………………………………………………
controler_task: (priority 2)
read data form a Sensory Queue and handle them, if there is no data available the task increases the binary semaphore   NeedSensoryData. Then it is blocked for 100ms Task 2………………………………..
sensory_task: (priority 1)
this one is responsible for reading the sensory data an add them into the queue. But this is only executed when the NeedSensoryData semaphore is set otherwise the task is blocked. Task 3…………………………………..
wlan_task: (priority 0)
this task should read incomming data form the wlan-module (rn131gsx) and process them. Incoming bytes (from connected wlan modul via rs232) are stored in an character queue. so the problem is: if I only start task1 and 2 everything is ok, but if i try to start the third task, the whole rtos system is crashing (but interrupts still work: LED is flashing if a byte is received) It would be grateful if somebody could help me.

CM3, rtos crashes after starting a third task

If you read through the forum you will find lots of posts where people are using a cortex and say it crashes when an interrupt is used. Especially on STM32. See item number 3 on the link http://www.freertos.org/FAQHelp.html

CM3, rtos crashes after starting a third task

Thank you for your help, but that’s not the problem.
I’m using another 2 different uarts for communication and reading the sensory data…the ISRs are complete the same except the used receive queues. So I can’t image that this is an interrupt problem.

CM3, rtos crashes after starting a third task

Sorry I’ve forgotten: including all 3 tasks the system is running for approximately 2 to 5 seconds until it crashes…maybe this is relevant