The inspector bug is that 1st time you invoke inspector, is that "g" key in the inspector is not using the same readtable as original invocation of inspector.
this patch _may_ fix your problem:
http://dwim.hu/gitweb/gitweb.cgi?p=slime;a=commitdiff;h=1d48273b30f46b2ea8a0...
in case i've rebased the repo meanwhile then:
"Fix: inspector uses the same thread and package that was used to invoke it (e.g. for svuc customizations depending on a transaction)."