Page hosted on IIS7.5 changes appearance on IIS6

Question

I'm in the middle of switching our site over to a new web server (Server 2008 R2), and am trying to copy one of the new applications to the old server (Server 2003) in order to let users access it in the meantime. The problem I'm running into is that even though I copied the folder over directly to the old server, started the app on the old server, and set the ASP.NET version to 4.0 to match what it's using on the new server, the old server displays the page differently. Specifically, the CSS styling (located in the head) that sets the font size and type is not utilized on the old server. On another page, a textarea is not displayed in the dimensions specified in the ASP.NET page; the style info just doesn't make it to the source code of the resulting page.

For example, here is the line of code in the aspx file:

<td colspan="3"><asp:TextBox ID="cre_slm_comm1" runat="server" Height="156px"
    TextMode="MultiLine" Width="400px" Text='<%# Eval("cre_slm_comm1") %>' /></td>

This is the resulting source code on the IIS6 server:

<td colspan="3"><textarea name="FormView1$cre_slm_comm1" rows="2" cols="20"
    id="FormView1_cre_slm_comm1">Test comment. 3/1/13. br.</textarea></td>

And the same line on the IIS7.5 server:

<td colspan="3"><textarea name="FormView1$cre_slm_comm1" rows="2" cols="20"
    id="FormView1_cre_slm_comm1" style="height:156px;width:400px;">
    Test comment. 3/1/13. br.</textarea></td>

Any suggestions on what I can do to fix the way these servers are not interpreting the code the same way?

Answer 1

Change the site application pool in IIS to target the same .NET Framework version and Pipeline of the other server.

or add this line in web.config:

<pages controlRenderingCompatibilityVersion="3.5" />

ASP.NET 4 Breaking Changes

Asp.net adapts the rendered html according to browser kind and version. check if it is related only to a browser.

If the problem persist maybe this could be a .net bug or the 2 server have some difference in the framework version(some patch etc etc).

Anyway an easy workaround and a best-practice IMHO is to use a css class to style an element.