ORA-04033: Insufficient memory to grow pool

DBAs, What is the reason for the below error.

OS = RHEL 4
Oracle = 11.2.0.1
DB runs on pfile.

SYS>alter system set streams_pool_size = 30m scope=both;
alter system set streams_pool_size = 30m scope=both
*
ERROR at line 1:
ORA-02097: parameter cannot be modified because specified value is invalid
ORA-04033: Insufficient memory to grow pool

sga_max_size                     big integer 140M
sga_target                           big integer 0
memory_max_target            big integer 0
memory_target                     big integer 0

Thanks in Advance!
Harry