Sigma releases service notice for latest telephoto lenses

Just thought I would share this info. The story caught my eye since I own a 150-500. My serial # is 10704867

From http://www.dpreview.co​m …1sigmatelephoto​notice.asp

Sigma has issued a notice warning customers of a 'potential autofocus defect' in some of its recently released telephoto lenses. The problem affects a some examples of the APO 50-500mm F4.5-6.3 DG OS HSM, APO 120-400mm F4.5-5.6 DG OS HSM and APO 150-500mm F5-6.3 DG OS HSM lenses. The company has listed the serial numbers of lenses that could be affected - owners experiencing problems with any of these lenses are being offered a free collection, inspection and service.

Press Release:
Auto focusing issue affects limited number of
Sigma telezoom lenses

After thorough investigation, we have ascertained that some APO 50-500mm F4.5-6.3 DG OS HSM, APO 120-400mm F4.5-5.6 DG OS HSM and APO 150-500mm F5-6.3 DG OS HSM lenses, produced recently, may have a potential autofocus defect.
This issue could possibly occur in some lenses within the following range of serial numbers:

List of lenses requiring the modification
APO 50-500mm F4.5-6.3 DG OS HSM: Serial Numbers between 10633051 and 10972000
APO 120-400mm F4.5-5.6 DG OS HSM: Serial Numbers between 10574001 and 10972000
APO 150-500mm F5-6.3 DG OS HSM: Serial Numbers between 10674301 and 10972000

This is a limited problem that will not occur in any lenses other than those specifically listed above.

Support for this problem
To overcome this issue, we will be offering our customers a modification service, free of charge. If one of our customers is experiencing an autofocus issue with one of the above lenses, we will rectify the situation through the help of our local authorized Sigma Service Stations.