the PDM acts crazy sometimes. it regularly will shot the wrong selections showing up in the wrong columns, etc. Fortunately it's not actually corrupting the data, it just freaks you out when you think you might be inadvertantly setting your labor hours to $599.
One way i've found to get it back "into shape" is to go back to columns/grouping, add or remove an arbitrary column, and when you save that setting the data seems to line back up.
if this is in fact what you running into, and your able to consistently recreate it, it would be good to post or email your steps to support so they can track it down and get it fixed in a future release. Its been a problem for quite some time now, but apparently its an elusive one.
(my bet is on indexing on 1 instead of 0 somewhere deep in the PDM code. any takers?

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