[igraph] graph attributes

[marco]

hi, 
i am trying to use the attributes with igraph C library, but i am not
successful.
If i initialize an igraph_attribute_table_t by using
igraph_i_set_attribute_table() i get segmentation faults (this does not
happen if i don't call it).
I know it can seem few detail but all i do is:
 initializing the table 
 creating a graph by igraph_empty()
 add edges loaded from a sql database

if i do those steps without attributes table the graph is created and i
can successfully use the igraph_clusters function on the graph. As soon
as i try to use attributes i get SIGSEGV.

any idea?

marco