It seems quite a few people here are unaware of this, however the rules for SR4 have been changed (Slightly) yet again. This was done something like 8 months ago or so.
Those who have not done so should check out the Shadowrun website as they offer a free PDF download with the changes introduced with SR4 Anniversary edition. There's also a fair bit of errata present for other books as well.
Notably SR4a lowered the cost of a few adept powers, altered the rules for extended tests, introduced a new vehicle, put a suggested cap on dice pools, assigned capacity rules to things like contact lenses, goggles, ear plugs in regards to augmentations that can fit in them etc. On the whole there are only 2 pages of changes, mostly minor yet still important.