Rabbit Core Module: programming issue

[Marco Trapanese]

Hi!

Before posting I read a lot of message several forums.
I run the Dynamic C 10.11 with a Rabbit Core Module RCM4100. I have
programmed several times the module on my own board composed of a 3V3
power supply, a LED connected to PE1 and nothing else. The /reset in is
unconnected as it is tied-up on the module itself.

I wrote a simple program to flash the led and it works fine. After
several programming cycles I can't connect to the processor anymore. The
IDE returns error while is sending Cold Loader.

If I remove the programming cable the led flashes as expected, so the
module is running. Furthermore:

+ both primary and RTC clock are running
+ power supply is ok
+ checked the PROG connector rather DIAG
+ checked the right COM port on laptop
+ the lapton has a native COM port, I don't use an USB serial converter
+ turned off, turned on after 1h: same error

If I move the module from my board to the Rabbit DevBoard I can program
it. Thus, I guess there is a problem with my board... But why I was able
to program before?

What should I check?

Thanks
Marco / iw2nzm