Segmentation fault

I am encountering segmentation fault due to address out of bounds in 
seems_valid_real function of octstr.c. The address of the octstr string in 
the calling function octstr_duplicate is alright. However, the call to 
seems_valid_real function generates the segmentation fault. Here is the 
information obtained while debugging:

  $1 = {data = 0x13 <Address 0x13 out of bounds>, len = 3, size = 2,
   immutable = 135084336}

Any known reasons for this?

Thanks and Regards,
Shashi Anand B