AF Microadjust or Bad Lens??

[Twstlok]

Hi all,
I mainly shoot sports with a 40D and 7D. I purchased a new Sigma 120-300mm f/2.8 from B&H last week. Of course right when I received it, a decent storm hit us here in the San Francisco Bay Area so the games I wanted to shoot were all rained out. I didn't fill out the warranty card when I got it because I wanted to be sure I didn't get a bad lens. A friend of mine bought the same lens for his Nikon and had to return it because of focus issues.
I shot some pics of our daughters riding their scooters and low and behold, the pics were blurry. Long story short, I tried using it yesterday at softball practice and, while it was focusing tack-sharp in the viewfinder, the pictures were quite blurry. I called B&H (they are awesome to deal with) who said I could return it but that this lens is now discontinued from Sigma due to an IS version coming out...but isnt out YET.
I dont have AF Microadjusting on my 40D but my 7D does. This is new to me, I've never had a lens not be tack-sharp when I've slapped it on my camera. Granted, they've all been Canon lenses and not 3rd party lenses.
Anyway, I'm about to try to determine if this is a micro adjusting issue (I hope so, the lens is great for me) or if I got a dud. If the lens is bad though, I'm wondering if I'm better off contacting Sigma for help? I want this lens and need its versatility. Has anyone dealt with any of these issues? Has anyone dealt with Sigma with good results? I paid $3,000 for a product of theirs that isnt functioning properly, I'd HOPE that they'd want to bend over backwards to fix it. Any and all input from you is appreciated and I'm NOT above admitting user error. I HOPE it's user error!
Cheers

[OsmosisStudios]

Examples with EXIF. Sounds like motion blur