I've checked my two systems both have sporder, one spelt SpOrder.dll in windows/system32 the other in c:/programme files/grisoft/avg. I use the pro version of AVG (7.5) and it has not identified any of these as a threat or trojan. I do n ot have a path system32/active scan.
I do not know the site, never used it only supplied link as it gave a description of sporder.dll. Looking at the link you gave it points to messages from 2005 - so it shows that AVG among others has identified the fil at times as a trojan. As VoG suggests this may be a case of a false positive by AVG.