SQLERRM shows nothing

Dear all,

I'm experiencing a strange issue with SQLERRM. I have a package with a procedure in which I have defined an exception handler using WHEN OTHERS. It looks basically like this:

WHEN OTHERS

 THEN lv_msg := substr(SQLERRM, 500);

            Log_Info(lv_msg);

            ln_retcode := 1;

Nothing complicated as such, but my problem is that the lv_msg is always "empty". If I do:

WHEN OTHERS THEN dbms_output.put_line(SQLERRM);

The output shows the error.

I've started using 11g for a couple of months now and I don't remember facing this problem on lower DB versions.

I'm just wondering if I'm losing it or if it's just those times when we miss the obvious!