I have two things.
1. Still no response to CLI if some kind of error happens. Error is seen only in log.
2. I am happy to see modifications, made by Freedom(?) (//Freedom Modify 2011-09-14 16:45)
I'd like to bring to Your attention that there still are some messages without span number in them.
As far I found those messages in desperate need of span number:
m20.c:98 gsm_message(gsm, "Cannot send SMS when not ready, waiting...\n");
m20.c:139 gsm_message(gsm, "Cannot send PDU when not ready, waiting...\n");
m20.c:776 gsm_message(gsm, "%s\n", data);
And their alternatives in simcom.c file. I have not checked sim900.c for those - I don't have such module.
I'd suggest to make something with \n in the last one, as modem already passes newline symbol, so this one makes simply empty newline.
Oh, and almost forgot even more important thing - no span number in errors in asterisk log. How can we know witch span is this error from?