I am using RH8 (with 8.0.2 patch applied) that uses SourceSafe for version control. I cannot create or import new snippets. I do get the dialog box which asks me to name the snippet or select a snippet for importing, but after I provide the information and click OK, nothing happens. RH does ask me if I want to check out the file "rhsnippet.apj", but nothing happens even when I click Yes. RH does look like it's trying to do something, but after a few seconds/minutes, I get the same dialog box again.
I also noticed that some snippets that I use in the project don't show up in the Snippets' window. I can edit them by going to the topic that has that snippet and click on it to edit. This is strange since the snippet doesn't show up in the Snippets' window, but RH still has that somewhere.
I am experiencing exactly the same problems. I cannot work out a way to make the importer work as it should, so I have resorted to creating dummy snippets and copying over the HTML manually.
As for the issue of snippets not appearing in the preview or edit windows, when this happened to me the snippet in question had been mysteriously deleted from the project (and VSS). The reason it's still in the Snippet list is because it's still referenced in 'rhsnippet.apj' (and probably your .CPD). In my experience, there's two ways around this:
Hope this helps until the actual bug is fixed (RoboHelp 9 maybe?)