From the steps shown, a sem_wait call was made, which results in a call to the kernel call SyncSemWait().  Since this is
 a kernel call, you won't have access to the source code for that call.  It would appear that the semaphore's value is 
currently 0, resulting in this thread's state becoming SEM BLOCKED.  You can confirm this state in System Information 
perspective, looking at the thread state information.
The thread cannot be stepped while it is in a blocked state.  So until some thread does a sem_post to the semaphore that
 your thread is blocked on, you will remain in that current state.

I also highly suspect that if you are using the VMWare target image that was downloaded from the QNX Software Center and
 you have applied updates to your base SDP 7 installation, that you have a mismatch between libc.so on the target and 
the libc.so symbols that the IDE is referencing.  While this is not a direct contributor to the specific behaviour that 
you are inquired about, if you have a mismatch it will cause other odd behaviour during debugging.