I have this problem in rev. 459 and some previous.
When i create a new circuit, add a pic component, load a file and run it, it works, there are some problems depending on the loaded program, but it works.
If i close the circuit document, and open it again then the simulation doesn't work; if i open the simbols viewer, i see all is working ok, all the register are doing what they have to, but in the circuit view all the pic pins stay low and nothing happens.
If i delete that pic and drag - drop a new one, load the file and run, it works... but when i close and open again the circuit, it doesn't work...