Recently been faced with an issue in OpenCart 1.5.0.5 which seems to affect these versions:
Opencart Version 1.5.0.1, 1.5.0.2, 1.5.0.3, 1.5.0.4, 1.5.0.5
The Error is a Javascript Error, if you don’t use something like FireBug then you will likely not notice the error.
The Erros is this though:
addModule is not defined
The problem this error will cause for certain will be that you cannot make / add new banners to your opencart store, this will affect anything and everything where you have hyphen’s and other special characters – for this reason – remove hyphen’s and special characters from your product options, categories and banner names and so on.
I’ve posted this on the BUG on the OpenCart 1.5.0.5 Bug Thread