Posted Depreciation is reversed

Hi

We got a problem for an asset whoseful life is expired in Nov 2012.The entire depreciation posted from Jan 2012 to Oct 2012 got reversed or posted wih "-"ve sign in Nov 2012. The depreiation amut from Jan 2012 to Nov 2012 updated as planned dep in Dec which is wrong

Useful life: 6 years

APC: 5,173,234.09

Monthly depreciation 71,850.47-

Actual dep start date - 1.12.2006

As of December 31, 2011, the netbook value of the asset was 788,970.18 THB

Also as of December 31, 2011, remaining useful life should be 11 Months i.e nov 2012.

788,970.18

NBV as of December 2011

January

(71,850.47)

Depreciaition

February

(71,850.48)

Depreciaition

March

(71,850.47)

Depreciaition

April

(71,850.47)

Depreciaition

May

(71,850.48)

Depreciaition

June

(71,850.47)

Depreciaition

July

(71,850.47)

Depreciaition

August

(71,850.48)

Depreciaition

September

(71,850.47)

Depreciaition

October

(71,850.47)

Depreciaition

70,465.45

NBV as of October 2012

November

718,504.73

All Depreciation postings (January - October) was reversed

December

(788,970.18)

Booking the entrie amount 2012 YTD

(70,465.45)

Difference between Nov and Dec 2012 (offsetting the value as of October

1. 0.00

NBV As of December 2012

We are using base method as "percentage from useful life" , period conrol is "period start" , multievel metod with base value "replacemen Value" but no cut of value key is assigned for dep key.

Please help us to understand why dep got reversed in Nov 2012?