Problems running Google Nav and streaming audio

[o2bnclemson]

I'm using a rooted Droid Eris 2.1 and frequently have problems with my Google Nav while using Pandora or other streaming media. The Nav will just freeze up or sometimes lag a few minutes behind where I actually am. I imagine those of you with faster processors don't have this problem, but those who have had this problem - does anyone know a good ROM, script or other solution for this?