I got the problem with round variance in 2009 AX . Usually the round variance is very tiny, but recently the variance become over $3,000 when we end work order, even thought we did not change any production setting up.
I sometimes have this problem, or at least a similar one, also. I know what appears to be happening, but I don’t know why. My Rounding Error variance is the sum of the values of the actual materials, actual labor and actual overhead dollars put into WIP for the order. When the order is ended, AX credits WIP for the standard cost of the finished good, and debits or credits the variance accounts properly (I have manually vlidated the variances). However, it also credits WIP for the actual material, labor and overhead and debits the Rounding Error account. This leaves a credit balance in WIP equal to the debit in the Rounding Error account that I have to make a journal entry to the Rounding Error account to offset.
You would have to look at the posting setup and the postings. WIP is reversed at End, nothing else goes back into WIP, but that does not mean you cannot configure a WIP account to be hit as part of the ending process of course. Difficult to comment really without knowing the data and the configuration of it.