The CM server contains: SDL Tridion 2011 SP1 and SiteEdit 2009 SP3. Since the templates are VBScript and using the 'old' SiteEdit, SiteEdit 1.3 SP1 is also installed. All according to the manuals.
The CM database was a 2009 GA version, which has been migrated to 2011 SP1 HR1. That's why SiteEdit v1.3 DLL is installed and registered. (SiteEdit and SiteEdit2 objects exists)
On the CM server, Tridion uses port 80, SiteEdit 2009 uses port 84.
BTW: It is not possible to install SiteEdit 1.3 SP1 on the CM machine because the installer doesn't recognize the CM website.
The problem is that the SiteEdit functionality is not shown nor working on the Presentation Server.
The PS server is a separate machine, with IIS7.5 and WebSphere. IIS has the /Images folder as its root, and therefore only serving the binaries. The IBM WebSphere plugin to redirect all traffic (for JSP, JS, CSS, etc.) to the WebSphere applicatie is installed. The staging website runs on port 81.
A simple plain JSP testpage is published to the PS server and available on port 81.
The source of the published page on the staging website contains the code:
<script defer="defer" id="_SE_Script" SRC="/SiteEdit/SiteEdit.js" SE="http://CM:84/|tcm:127-462398-64|1|tcm:0-134-65537|1|1|1|0|1|#AAAAAA|black|#EECCCC|red|#EEAAAA|#00AA00|#AAEEAA"></script>
The tcm id's of the page and the publication target are correct.
There is of course no /SiteEdit/SiteEdit.js on the PS server....
Since I'm writing this, I suspect that the SE URL should be something like, SRC="http://CM:84/SiteEdit/SiteEdit.js" because that URL is a valid URL for the CM server.
In IIS Manager > Sites > SiteEdit 2009 SP3 > has virtual directory /SiteEdit which points to the SiteEdit folder within the SiteEdit 2009 folder.
The old 2009 GA server has a physical file called /SiteEdit/SiteEdit.js
There a several web.config's edited, I'll guess there too big and too much to display here.
The SiteEdit 2009 web.config has a:
<add key="UrlToHide" value="/.*SiteEdit/SiteEdit.js"/>
Any tips for debugging and solving this issue?
The culprit is the /SiteEdit/SiteEdit.js which doesn't exists on the PS server (in this case the WebSphere Application Server).
Update 2013-06-25:
Changed the SiteEdit URL on the Presentation Server, from relative /SiteEdit/SiteEdit.js to absolute: CM:84/SiteEdit/SiteEdit.js (http:// in front of CM:84 is not accepted by StackExchange).
So the script tag reads:
<script defer="defer" id="_SE_Script" SRC="http://cms:84/SiteEdit/SiteEdit.js" ... />
Calling this absolute URL via Internet Explorer on the PS machine or the CM machine results in http error 503 server unavailable.
/SiteEdit/EditEdit.js
(as Peter says) and return a 404. This is normal behavior for you combination (SiteEdit 1.3 building blocks with a SiteEdit 2009 front-end), so please ignore that part in your further analysis. The 503 error typically comes with more details in the Windows event viewer.