Using "clock save interval" to back up running time to nvram causes GNS3 to become unresponsive and die a miserable death.

Image:
Cisco IOS Software, 3700 Software (C3725-ADVSECURITYK9-M), Version 12.4(3), RELEASE SOFTWARE (fc2)

GNS3 0.8.7 emulating:
Cisco 3725 (R7000) processor (revision 0.1) with 124928K/6144K bytes of memory.
Processor board ID FTX0945W0MY
R7000 CPU at 240MHz, Implementation 39, Rev 2.1, 256KB L2, 512KB L3 Cache
2 FastEthernet interfaces
DRAM configuration is 64 bits wide with parity enabled.
55K bytes of NVRAM.
16384K bytes of ATA System CompactFlash (Read/Write)

Running on Windows 7 64-bit