I suspect you may be right. It have never heard of a project with the same requirements. Nearly 500 snippets is a lot. How the hell can you manage a project with that many? Don't get me wrong. Maybe your requirements warrent that many. I am just thinking of the difficulty in finding and selecting one when you need to use one.
You could try ensuring that you have the option set to rebuild your project's CPD file each time you open the project (Tools > Options). It could be that the sheer number of snippets is causing the CPD file to grow exponentially.
Thanks for the advice Peter, but deleting the CPD does not fix the issue. I have 500 snippets because I have 500 fields (and growing all the time) to document that can appear in multiple reports and also require that each field is documented separately. So although I seem to be pushing the envelope with the amount of snippets, I am grateful for the existence of snippets because trying to document this without snippets would be a nightmare!
One thing that annoys me is that you cannot apply a style sheet to multiple snippets at the same time. At least I have not found a way. Is there a way of doing this – short of editing the HTML for each snippet individually? I will add this to a feature request for RoboHelp as well as log a bug report with Adobe.
Normally the snippet picks up the CSS styling from the topic the snippet appears in. For example, if the topic CSS says the text should be purple, the snippet text will be purple. But if a different topic CSS says the text should be red, the same snippet text would be red. Assuming there were no classes added to the snippet code.