Cisco Switch: How To Stack Two 3750 Switches

I was asked recently by a customer to stack two Cisco 3750s and get them ready for re-purposing. So the first thing I did was to look at the IOS versions on both to verify the firmware was the same.  They were not.  This is what they had:
unit 1: "flash:c3750-ipservicesk9-mz.122-55.SE5.bin"
unit 2: "flash:c3750-ipservicesk9-mz.122-55.SE1.bin"

So I tftp'ed the SE5.bin version to my laptop and then put it on unit 2 so that they would match.  You have to have them match if you want them to stack.  Once I had both images the same, I then erased the config on both of them.

switch#wr erase
Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]
[OK]
Erase of nvram: complete
System configuration has been modified. Save? [yes/no]: no
Proceed with reload? [confirm]

Once I wiped the config on both units and reloaded them, I then kept power on unit 1 and powered down unit 2.  I connected the stacking cables as shown in the picture below.  Once connected, I powered unit 2 up and let the stack form.
*Mar  1 00:09:17.951: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 1 Switch 1 has changed to state UP
*Mar  1 00:09:17.951: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 1 has changed to state UP
*Mar  1 00:10:07.612: %STACKMGR-4-SWITCH_ADDED: Switch 2 has been ADDED to the stack
*Mar  1 00:10:14.767: %STACKMGR-5-SWITCH_READY: Switch 2 is READY
*Mar  1 00:10:14.767: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 1 Switch 2 has changed to state UP
*Mar  1 00:10:14.767: %STACKMGR-4-STACK_LINK_CHANGE: Stack Port 2 Switch 2 has changed to state UP
*Mar  1 00:10:15.799: %STACKMGR-5-SWITCH_READY: Switch 1 is READY (Switch-2)
*Mar  1 00:10:15.899: %STACKMGR-5-MASTER_READY: Master Switch 1 is READY (Switch-2)
*Mar  1 00:10:15.883: %STACKMGR-5-SWITCH_READY: Switch 2 is READY (Switch-2)
*Mar  1 00:10:19.741: %CFGMGR-4-SLAVE_WRITING_STARTUP_CFG: only master can do that (Switch-2)
*Mar  1 00:10:19.741: %CFGMGR-4-SLAVE_WRITING_STARTUP_CFG: only master can do that (Switch-2)