After you disconnected the iPod from the iMac, did the iMac boot up okay?
It could be an indication or a damaged or dying hard drive. I would recommend doing a disk diagnostic on the iPod's HD using the instructions given by turingtest2 in this older thread. He also covers what the resulting numbers indicate.
If necessary, post the resultings numbers and we can verify what the next steps to take.
Tried all the above.
Pending sectors --7
Start Stops -- 1941
Disk Repair found no problems.
I have movies,videos,music,audio books and podcasts all loaded on now and no pictures with 45.2GB free space. I'm going to leave things as they are and see how it all works during the next week.
The iPod Nano and iPod Touch have had no issues and work fine using the same computer and iTunes and iPhoto.
Had to restore the iPod Classic this evening. It has been slow ejecting the past couple of times it was unplugged.
So it's not the pictures that is causing the problem. Guess it is the hard drive going bad which is a big disappointment. This iPod is not even 3 years old but it does get alot of use all week long. Maybe it's time for a new iPod. Wish Apple would update the iPod Classic before I get a new one.
Tried the low level format. After following the instructions then syncing the ipod I disconnected it and got a check mark on the screen. Reconnected it and had to restore it. Started the restore and the computer shut down. Restarted everything and finished the sync with podcasts only. Everything was OK then except now I can hear the ipod hard drive clicking. Adding the music onto the iPod now.
Here is part of the crash report from the iPod I just tried to sync.
Process: iTunes 
Version: 10.7 (10.7)
Build Info: iTunes-10702101~1
Code Type: X86 (Native)
Parent Process: launchd 
Date/Time: 2012-11-18 18:39:31.025 -0500
OS Version: Mac OS X 10.6.8 (10K549)
Report Version: 6
Interval Since Last Report: 249500 sec
Crashes Since Last Report: 6
Per-App Interval Since Last Report: 460340 sec
Per-App Crashes Since Last Report: 6
Anonymous UUID: 36BFD4AA-BABA-4FA9-87DE-819C4CB07FCC
Exception Type: EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x00