Please share your PSoC Creator project with us to understand why the IDE is set . It is difficult to comment on this issue without looking into your project
Also let us know what is the AMR and ACR value you are observing .
Please have a look into the following forum post to understand how AMR and ACR are set - http://www.cypress.com/?app=forum&id=2232&rID=82079
Thanks for your answer. I'm sorry I can't publish my source code. But anyway, I think I was accessing the registers in a wrong way, that's why I came up with the question in the headline. Now the AMR and ACR registers behave like they should!
(just another tip for people working on that, too: when writing these registers it is highly recommended to use the RXRegisterInit function, otherwise strange side-effects will occur)