DivaVocals:
Have you double checked that other mods you are running are not overwriting the same files needed by IH2?? If that's the case you will need to use a tool like Winmerge to merge the affected files..
Yes I did. Look, I read all the posts in here. I'm not a newbie when it comes to these things. I could say that the only "change" I did when installing the mod is when I inserted two files from the includes/modules folder into my template folder.
additional_images.php
& product_main_image.php
I had additional_images.php already overridden, meaning it was in modules/my_template. So I renamed my already modified file to something else to disable it and put the IH related file instead.
On the other hand I saw that I don't have product_main_image.php overridden and that according to the IH pack it suppose to overwrite the default file under /modules so prior to uploading the files to my server I had moved it to modules/my_template.
All in all I don't think it affects the problem.