If I understood correctly-

It was confirmed that an asset cannot be disposed of during the same period it was acquired (regardless of the length of that period). An end of period process must be run first. OK, that's exactly as I thought.

But now the second part of the original question, I'm still unclear on. Simple example:

In January you acquire an asset for $1,200, you enter it into Fixed Assets and do a period (month) end close. In March you are billed an additional $1,200 for that same asset. Can the asset value be increased and the depreciation updated to reflect what would have happened if the entire 2,400 was entered in January? (i.e monthly depreciation as booked would have been 100/mo when it should have been 200/mo). Didn't say it was a realistic example - but it is representative of what the client says they experience.

Thanks for your help.