This might explain why I lost both WRX engines to spun rod bearings at Mosport's GP track and I had no issue with my '09 STi there. I ran the STi many more times at the GP track there than the WRX.
http://www.killerbmotorsport.net/blog/oilpanidentifier/
"Background
Subaru oiling systems have evolved over the time since the introduction of the EJ engine since its introduction in 1989. From a performance perspective, improvements have been made and a general statement can be made that more recent versions offer a performance advantage over older versions. This follows the performance progression over time as WRX and STi models have increased performance. As far as which oil pan will fit which engine, ALL EJ engines are the same from the bottom. They all share the same oil pan (and oil pickup) mating surface geometry, and bolt patterns. If changing to a newer version oil pan, you must always use the oil pickup made for that pan, not for that year engine. Same holds true for the dipstick and dipstick tube (if you want to retain OEM level accuracy; you an always scribe your new ‘full’ mark on an old dipstick). In other words, the oil pickup part number to be used needs to be for the oil pan it is made to be used with." [KillerB]