Your issue with the related items module is down to the itemid in the read more link
Each menu has its own item id. When you access an item of content from e.g. a blog page called History, it will have an item id equal to that of the blog page history and therefore will display the same modules as the blog page history.
I assume that your problem is that when you access the item from the frontpage read more link, it is getting an itemid equal to that of the frontpage and therefore displays the frontpage modules.
I do not fully understand how the itemid is allocated. I have one site where some items on the frontpage have a frontpage itemid and others where they have the correct itemid for its section. I cannot follow what circumstances cause an item id equal to the frontpage.
Maybe someone can give a way of influencing it but if not, a few work arounds that I can think of are:
1: Publish the related items module on the frontpage too - that way when viewing content via frontpage read more... link, it will have the same modules as the frontpage.
2: If the items on the frontpage are remaining fairly static, you could choose not to show the automatic read more links and add your own read more... links, hard coded into the bottom of the intro text with the correct itemid.
3: If you do not want the module on the frontpage, you could use a conditional statement to only include the module position for the related items module on certain types of page output.
e.g.
you could add the following code into your template index file:
Code:
<?php if ($option =="com_content") { mosLoadModules ( 'user7' ); }; ?>
This would then only load the module position user7 on pages output with com_content. You can publish the module to the position user7 on the homepage (and other pages where you want it) and it will not show when viewing the normal homepage, but will show when viewing an item via the read more link with a homepage itemid because it uses com_content. The downside to this is that the other frontpage modules will show too.
Obviously it would be best if someone could help you on how to influence the itemid in frontpage items rather than work around it. I actually requested that someone on the forum should create an FAQ about itemid issues because it keeps cropping up and yet there is a lack of firm info on it. Nobody has taken up the request as far as I know.