Maybe I'm doing it wrong, but that dosen't work either....
I just tried both ways, and it worked form me.
<TABLE style="WIDTH: 479pt; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=635 border=0 x:str><COLGROUP><COL style="WIDTH: 34pt; mso-width-source: userset; mso-width-alt: 1645" span=11 width=45><COL style="WIDTH: 9pt; mso-width-source: userset; mso-width-alt: 438" span=2 width=12><COL style="WIDTH: 20pt; mso-width-source: userset; mso-width-alt: 987" width=27><COL style="WIDTH: 67pt; mso-width-source: userset; mso-width-alt: 3254" width=89><TBODY><TR style="HEIGHT: 15pt" height=20><TD class=xl66 style="BORDER-RIGHT: black 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; WIDTH: 102pt; BORDER-BOTTOM: windowtext 0.5pt solid; HEIGHT: 15pt; BACKGROUND-COLOR: transparent" width=135 colSpan=3 height=20 x:num="40184">
01/06/2010</TD><TD class=xl69 style="BORDER-RIGHT: black 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: windowtext; WIDTH: 68pt; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" width=90 colSpan=2 x:fmla="=YEAR(A1)" x:num>
2010</TD><TD class=xl73 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; WIDTH: 68pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=90 colSpan=2>
"=year(g39)"</TD><TD class=xl65 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 34pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=45></TD><TD class=xl65 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 34pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=45></TD><TD class=xl65 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 34pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=45></TD><TD class=xl65 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 34pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=45></TD><TD class=xl65 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 9pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=12></TD><TD class=xl65 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 9pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=12></TD><TD class=xl65 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 20pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=27></TD><TD class=xl65 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 67pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=89></TD></TR><TR style="HEIGHT: 15pt" height=20><TD class=xl66 style="BORDER-RIGHT: black 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BORDER-BOTTOM: windowtext 0.5pt solid; HEIGHT: 15pt; BACKGROUND-COLOR: transparent" colSpan=3 height=20 x:num="40185">
01/07/2010</TD><TD class=xl71 style="BORDER-RIGHT: black 0.5pt solid; BORDER-TOP: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BORDER-BOTTOM: windowtext 0.5pt solid; BACKGROUND-COLOR: transparent" colSpan=2 x:fmla="=A2" x:num="40185">
2010</TD><TD class=xl75 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: windowtext; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" colSpan=10>
"=g40" formatted using right click, custom and tying "yyyy"</TD></TR></TBODY></TABLE>
Maybe its a setting thing??