you should probably update to the latest version of Netos 7.5.2 and install all the patches (please open a support call to get the link to the latest version). To debug your problem try using a module with JTAG and try to reproduce the problem in the debugger with breakpoint in critical sections like exception handlers and crash(); You reset might be due to a hardware whatchdog. Try adding various printf statements if you have access to serial console, otherwise you can printf via udp