May need to reduce the core clock a bit from 900Mhz on a 5970 as the recent MilkyWay tasks may be more stressful than the ones in the past and certainly much more demanding on hardware than PrimeGrid. With the very fast purging of tasks here you need to watch very carefully to notice occasional tasks that appear to complete and report successfully but do not validate due to hardware errors.

I've noticed this too and have had to dial back the clocks on all my boxes. Still, there's more validation errors than there used to be.

Since my last post in this thread my value for "consecutive valid tasks" was not reseted once, I was watching it, it's ATM at 172 and I'm doing 80-100 WUs a day. So for this calculation should be right, my value should have been after this 7 days somewhere around 560-700. But it's not, not even close to that.

Link have you watched it 24 hours continious? Past week I could'nt sleep and watched it for 2.5 hours on two screens. One with the BOINC manager and the other with the tasks list and presed F5 every time 2 tasks where sent from the BOINC tray. And found no error. The CVT (consecutive valid tasks) did not increase with every validated task.
Today I found a first validate error and the CVT was reset to 1. (The max tasks per day not to 10000).
Now half an hour later several tasks are validated (credit has increased) but the CVT is still 1.
Have you an idea?

MilkyWay@Home 0.82 windows_x86_64 (ati14)
Number of tasks completed 7653
Max tasks per day 17748
Number of tasks today 2016
Consecutive valid tasks 662
Average processing rate 431.94021858927
Average turnaround time 0.01 days

From my observation (and I'm looking quite carefully right now, as I'm testing a new system), the real number of consecutive valid tasks is "Max tasks per day" - 10000. That's the part I'm 99% sure about.