Here is the latest from Canon in regards to the 'squeak.' Apparently a 'squeak' to me, is a mechanical sound to Canon. We live in a strange world… for reference I've posted a link to a video of the squeak er uh… I mean... mechanical sound. Most expensive mechanical sound I ever paid for! :

__________
Canon 24-70 2.8 USM II Lens Squeak (2)
__________
Dear Mark Shaw:
We appreciate your continued correspondence.
I understand your concern. The sound we are both referring to is not considered a "squeak". The lens as it moves will make a mechanical sounds, but not a squeaking sound. Squeaking to me would be a higher pitched sound. The lens was just returned from the repair facility. Regrettably, the only option we are left with would be sending the camera back to the repair facility for a repeat repair. If you would like to receive the shipping label, please provide the following information.
Product Serial Number:
Date of Purchase:
Address:
City:
State:
Zip:
Phone Number:
We look forward to your reply with the information we have requested regarding your PowerShot SD4000 IS.
-----------------------------------------------------
We look forward to your reply with the information we have requested.
Sincerely,
Ronald
Technical Support Representative
Special Note: Certain issues are very difficult to resolve via email. If you would prefer to speak to a technician for additional assistance, you may call our special toll-free number for email customers with unresolved issues by dialing 1-866-261-9362, Monday - Friday 10:00 a.m. - 10:00 p.m. ET (excluding holidays).