Too Many Model Loads?

[eluser]datguru[/eluser]
Hi there,

Is there a limit to how many Models you can load? For some reason when I try to load the models in my current code it comes up with

An Error Was Encountered

The model name you are loading is the name of a resource that is already being used: mdl_products

Any Ideas why this would be I can paste the code but its quite alot so just wondered if anyone had any general ideas?