<p>I have been using <a href="http://www.plt-scheme.org/" rel="noreferrer">PLT Scheme</a>, but it has some issues. Does anyone know of a better implementation for working through SICP?</p>

Use
MIT Scheme
.
It's recommended by the authors of SICP, and is used at MIT for the
6.001: Structure and Interpretation of Computer Programs
course.