EF 70-200mm f/4 L production issues with stock from last 6 months

[onefivenine]

Just a heads up.
Mate of mine has a 70-200mm F4 L IS on back order from warehouse exp.
He was advised in no uncertain terms not to buy one of these lenses from current stock anywhere (especially Hong Kong sourced) as Canon have reported serious production flaws in batches from the last 6 months. This affects IS and non-IS F/4 L's. The f/2.8's don't have this problem.
Thought I'd share this.

[stebbo2]

Mine came from Kerso about 4 months ago - no problems as far as I can tell. What should I be looking out for?

[onefivenine]

I don't know the specifics sorry, actually I'm quite tempted to phone warehouse myself to ask a few questions. From what my mate told me the flaws are apparently pretty horrendous, so if you haven't noticed anything by now then your one is fine! It's supposedly hit-and-miss and certain batches are affected.