My Router cisco 2811 has this problem.
Log Buffer (51200 bytes):
Aug 27 19:38:53.649: %SYS-2-MALLOCFAIL: Memory allocation of 780 bytes failed from 0x40327608, alignment 32 Pool: I/O Free: 7504 Cause: Memory fragmentation Alternate Pool: None Free: 0 Cause: No Alternate pool
-Process= "Pool Manager", ipl= 0, pid= 6
-Traceback= 0x411B2D30 0x400A76C0 0x400ABBE8 0x40327610 0x400C9668 0x400ABBE8 0x40327610 0x400C9668 0x400C97CC
it's slow and refused the telnet session.
I'm using this as a voice gateway