We are on SP1 with June 2011 CU in our PS 2010 environment. I agreed with you that % COMPLETED should at least have some values since resouces did report progress even if just one of them. The odd part was that if RES A puts 50% and RES B puts 30, then the % COMPLETED will take the lower value. % Work Completed is showing the correct aggregate in my case.
I will try this out with FIXED WORK and FIXED UNIT typed tasks too. Once I completed my testing, I will post to the community on my findings.
