I've sometimes seen issues when cloning and changing the size at the same time. If possible first image your current large drive so you have a backup. Then use a partition manipulation utility like bootit-ng (the trial version is fully functional, you can use this tool to do everything, by the way, from cloning to imaging too) to resize your partition to around 160GB (preferably less). When that is done, reboot the PC to check if everything is still OK. If yes, do your cloning after that.
http://terabyteunlimited.com/