gridview column extends page for miles

I have a gridview with a label in it that is extending it's content page as well as the master page for miles across when there is a continuous entry of characters without spaces.  For example 100 d entries, dddddddddddddd....

 I've tried adding item-style wrap and item-style width to the field, but doesn't help, those d's just go straight across without breaking to next line.

I have to have whatever is entered, regardless of how bizarre the entry may be, so no truncation.

Is there a way to break to next line after so many chars?  I would have thought the item-style settings would have fixed, but no.

thanks

<ajax:UpdatePanel ID="updatePanelSecurityGroups" runat="server" UpdateMode="Conditional">
        <ContentTemplate>
            <asp:GridView ID="_gridViewClientSecurityGroups" runat="Server" Width="100%" AutoGenerateColumns="False" OnRowCommand="_gridViewClientSecurityGroups_RowCommand" OnRowDataBound="_gridViewClientSecurityGroups_RowDataBound">
                <Columns>
                    <asp:TemplateField HeaderText="Group Name">
                        <ItemTemplate>
                            <b><asp:Label ID="LabelGroupName" runat="Server"><%# Eval("SHORT_NAME")%></asp:Label></b><br />
                            <asp:Label ID="LabelDescription" CssClass="dataTableSmall" runat="Server"><%# Eval("Description")%></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:BoundField DataField="CLIENT_SHORT_NAME" HeaderText="Client" />
                    <asp:TemplateField HeaderImageUrl="~/Library/Key.gif" ItemStyle-Width="0%">
                        <ItemTemplate>
                            <asp:HyperLink ID="HyperLinkMangePermissions" runat="Server" ImageUrl="~/Library/Key.gif" ToolTip="Manage Permissions" ></asp:HyperLink>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:BoundField DataField="ASSOCIATE_COUNT" HeaderText="Members" ItemStyle-Width="0%" ItemStyle-HorizontalAlign="Center" />
                    <asp:BoundField DataField="CREATED_BY" HeaderText="Created By" />
                    <asp:TemplateField HeaderImageUrl="~/Library/Icon-Trash.gif" ItemStyle-Width="0%">
                        <ItemTemplate>
                            <asp:ImageButton ID="ImageButtonDeleteGroup" runat="Server" ImageUrl="~/Library/Icon-Trash.gif" AlternateText="Delete" CommandName="DeleteGroup" CommandArgument='<%# Eval("SECURITY_GROUP_ID") %>' />
                        </ItemTemplate>
                    </asp:TemplateField>
                </Columns>
            </asp:GridView>
        </ContentTemplate>
    </ajax:UpdatePanel>