We have a dynamic Component Presentation, inside which we are using a helper function.
This helper function calls a RenderComponentPresentation("tcm:1-2", "tcm:1-4-32").
The Component Template tcm:1-4-32 happens to be a dynamic one, but it is behaving like a static Component Presentation; no TCDL tag is being written out (the results are written out directly). Therefore, no changes are being updated when publishing component "tcm:1-2."
As far as I can tell, the razor mediator just uses the RenderComponentPresentation method of the Tridion Engine, so it should just work the same as for the DWT mediator. I haven't had time to dive into the details, but if you want to do so yourself, I'd start here: https://code.google.com/p/razor-mediator-4-tridion/source/browse/trunk/Tridion.Extensions.Mediators.RazorMediator/Tridion.Extensions.Mediators.RazorMediator/Models/ComponentPresentationModel.cs#156
Beyond that - if you think this might be a bug in the razor mediator, please report it at https://code.google.com/p/razor-mediator-4-tridion/issues/list
I'd strongly recommend downloading the entire project and loading it in Visual Studio. It's not difficult code for an experienced programmer to follow (thanks @alex-klock) and you may very well be able to figure out the answer for yourself. If you have a proposed fix, please submit it to the google-code project - there are several committers who may be able to make the time to review it.
RenderComponentPresentationbut to be sure, does is the Component Template reference the schema fortcm:1-2and is checked in? Check with the Razor Mediator site or @AlexKlock--I couldn't find anything that confirmed RenderComponentPresentation changes into matching tcdl syntax. Does the RenderCP call work on pages?