; caught STYLE-WARNING: ; SB-THREAD:GET-MUTEX has been deprecated as of SBCL 1.0.37.33. Use ; SB-THREAD:GRAB-MUTEX instead.
The attached patch requires 1.0.38, which appears to have been released April 2010.
Support for 2.5+ year old compilers may or may not be desirable when weighed against a style-warning. I don't have a strong opinion.