I'm having the same problem, anyone?
******In \Exchange2007\ClientAccess\Owa\forms\premium
\editmessage.aspx*********
******Change this Block of code (search for bcc)**********
<tr id="trBcc" <%= ShowBcc ? "" : " style=\"display:none\"" %>>
			<td class="tdABB">
				<a id="btnBcc" class="flat btn <%=UserContext.IsRtl ? "r" : "l"%>"
<%RenderOnClick("shwABM(\"divBcc\");");%> hidefocus="true"
tabindex="-1" href="#">
					<img align=absmiddle src="<
%UserContext.RenderThemeFileUrl(Response.Output,
ThemeFileId.AddressBook);%>"> <
%=LocalizedStrings.GetHtmlEncoded(Strings.IDs.BccEllipsis)%>
				</a>
			</td>
			<td>
				<%
				if (ShowBcc)
					RecipientWell.Render(Response.Output, UserContext,
RecipientWellType.Bcc);
				else
					RecipientWell.Render(Response.Output, UserContext,
RecipientWellType.Bcc, RecipientWell.RenderFlags.Hidden);
				%>
			</td>
		</tr>
******To This************
<tr id="trBcc">
			<td class="tdABB">
				<a id="btnBcc" class="flat btn <%=UserContext.IsRtl ? "r" : "l"%>"
<%RenderOnClick("shwABM(\"divBcc\");");%> hidefocus="true"
tabindex="-1" href="#">
					<img align=absmiddle src="<
%UserContext.RenderThemeFileUrl(Response.Output,
ThemeFileId.AddressBook);%>"> <
%=LocalizedStrings.GetHtmlEncoded(Strings.IDs.BccEllipsis)%>
				</a>
			</td>
			<td>
				<% RecipientWell.Render(Response.Output, UserContext,
RecipientWellType.Bcc); %>
			</td>
		</tr>
**************************
Now BCC is on by default and can be turned off in options.