sbcl compilation problem

This time it's sbcl (again, clsql v 4.3.3., linux-x86):

;/home/simon/.fasls/sbcl-1.0.30-2.fc12-linux-x86/home/simon/lisp_packages/clbuild/source/clsql/db-postgresql/postgresql-sql.fasl written
; compilation finished in 0:00:03.991
WARNING:
    COMPILE-FILE warned while performing #<COMPILE-OP NIL {B0A8949}> on
    #<CL-SOURCE-FILE "postgresql-sql" {B0402C1}>.

debugger invoked on a ASDF:COMPILE-FAILED in thread #<THREAD "initial thread"
RUNNING {A903811}>:
   erred while invoking #<COMPILE-OP NIL {B0A8949}> on
   #<CL-SOURCE-FILE "postgresql-sql" {B0402C1}>

Type HELP for debugger help, or (SB-EXT:QUIT) to exit from SBCL.

restarts (invokable by number or by possibly-abbreviated name):
   0: [TRY-RECOMPILING] Try recompiling postgresql-sql
   1: [RETRY          ] Retry performing #<ASDF:COMPILE-OP NIL {B0A8949}> on
                        #<ASDF:CL-SOURCE-FILE "postgresql-sql" {B0402C1}>.
   2: [ACCEPT         ] Continue, treating #<ASDF:COMPILE-OP NIL {B0A8949}> on
                        #<ASDF:CL-SOURCE-FILE "postgresql-sql" {B0402C1}> as
                        having been successful.
   3: [ABORT          ] Exit debugger, returning to top level.

((SB-PCL::FAST-METHOD ASDF:PERFORM (ASDF:COMPILE-OP ASDF:CL-SOURCE-FILE))
  #<unavailable argument>
  #<unavailable argument>
  #<ASDF:COMPILE-OP NIL {B0A8949}>
  #<ASDF:CL-SOURCE-FILE "postgresql-sql" {B0402C1}>)
0] back

0: ((SB-PCL::FAST-METHOD ASDF:PERFORM (ASDF:COMPILE-OP ASDF:CL-SOURCE-FILE))
     #<unavailable argument>
     #<unavailable argument>
     #<ASDF:COMPILE-OP NIL {B0A8949}>
     #<ASDF:CL-SOURCE-FILE "postgresql-sql" {B0402C1}>)
1: ((LAMBDA
         (SB-PCL::.PV. SB-PCL::.NEXT-METHOD-CALL. SB-PCL::.ARG0.
          SB-PCL::.ARG1.))
     #<unavailable argument>
     #<unavailable argument>
     #<ASDF:COMPILE-OP NIL {B0A8949}>
     #<ASDF:CL-SOURCE-FILE "postgresql-sql" {B0402C1}>)
2: ((SB-PCL::FAST-METHOD ASDF:PERFORM ASDF:AROUND
      (ASDF:COMPILE-OP ASDF:CL-SOURCE-FILE))
     #<unavailable argument>
     #S(SB-PCL::FAST-METHOD-CALL
        :FUNCTION #<CLOSURE # {AFAB4A5}>
        :PV NIL
        :NEXT-METHOD-CALL NIL
        :ARG-INFO (2))
     #<ASDF:COMPILE-OP NIL {B0A8949}>
     #<ASDF:CL-SOURCE-FILE "postgresql-sql" {B0402C1}>)

etc.

Here's what I see while sbcl is compiling postgresql-sql.lisp

[...]

; file:
   /home/simon/lisp_packages/clbuild/source/clsql/db-postgresql/postgresql-sql.lisp
; in:
;      DEFMETHOD DATABASE-WRITE-LARGE-OBJECT (T STRING POSTGRESQL-DATABASE)
;     (=
;      (PGSQL:LO-WRITE CLSQL-POSTGRESQL::PTR CLSQL-POSTGRESQL::FD
;                      CLSQL-POSTGRESQL::DATA LENGTH)
;      LENGTH)
; ==>
;   LENGTH
; 
; note: deleting unreachable code
; 
; note: deleting unreachable code

;     (IF CLSQL-POSTGRESQL::RESULT "commit" "rollback")
; ==>
;   "commit"
; 
; note: deleting unreachable code

;     (PGSQL:LO-WRITE CLSQL-POSTGRESQL::PTR CLSQL-POSTGRESQL::FD
;                     CLSQL-POSTGRESQL::DATA LENGTH)
; --> BLOCK LET LET LET LET CFFI-SYS:%FOREIGN-FUNCALL
; --> CFFI-SYS::%%FOREIGN-FUNCALL ALIEN-FUNCALL
; --> SB-C::INVOKE-WITH-SAVED-FP-AND-PC LAMBDA FUNCTION
; --> SB-ALIEN-INTERNALS:NATURALIZE LET LET LET LET
; --> SB-ALIEN-INTERNALS:MAYBE-WITH-PINNED-OBJECTS PROGN SB-C:%ALIEN-FUNCALL
; ==>
;   (SB-ALIEN-INTERNALS:DEPORT #:G833
;                              '#<SB-ALIEN::ALIEN-SYSTEM-AREA-POINTER-TYPE
;     SYSTEM-AREA-POINTER>)
; 
; caught WARNING:
;   Asserted type SB-SYS:SYSTEM-AREA-POINTER conflicts with derived type
;   (VALUES STRING &OPTIONAL).
;   See also:
;     The SBCL Manual, Node "Handling of Types"

[...]

;/home/simon/.fasls/sbcl-1.0.30-2.fc12-linux-x86/home/simon/lisp_packages/clbuild/source/clsql/db-postgresql/postgresql-sql.fasl written
; compilation finished in 0:00:03.991
WARNING:
    COMPILE-FILE warned while performing #<COMPILE-OP NIL {B0A8949}> on
    #<CL-SOURCE-FILE "postgresql-sql" {B0402C1}>.

Andras