diff --git a/src/libcore/vec.rs b/src/libcore/vec.rs
index 494470e32e4..a2e7a20bdf2 100644
--- a/src/libcore/vec.rs
+++ b/src/libcore/vec.rs
@@ -385,7 +385,6 @@ fn shift<T>(&v: [T]) -> T {
             let mut r <- *vv;
 
             for uint::range(1u, ln) {|i|
-                // FIXME (#2703): this isn't legal, per se...
                 let r <- *ptr::offset(vv, i);
                 push(v, r);
             }
diff --git a/src/rt/rust_builtin.cpp b/src/rt/rust_builtin.cpp
index cab1b6b427c..ad729494c45 100644
--- a/src/rt/rust_builtin.cpp
+++ b/src/rt/rust_builtin.cpp
@@ -891,9 +891,7 @@ rust_unlock_cond_lock(rust_cond_lock *lock) {
 extern "C" void
 rust_wait_cond_lock(rust_cond_lock *lock) {
     rust_task *task = rust_get_current_task();
-#ifdef DEBUG_LOCKS
-    assert(lock->lock.lock_held_by_current_thread());
-#endif
+    lock->lock.must_have_lock();
     assert(NULL == lock->waiting);
     lock->waiting = task;
     task->block(lock, "waiting for signal");
@@ -905,9 +903,7 @@ rust_wait_cond_lock(rust_cond_lock *lock) {
 
 extern "C" bool
 rust_signal_cond_lock(rust_cond_lock *lock) {
-#ifdef DEBUG_LOCKS
-    assert(lock->lock.lock_held_by_current_thread());
-#endif
+    lock->lock.must_have_lock();
     if(NULL == lock->waiting) {
         return false;
     }
diff --git a/src/rustc/middle/trans/base.rs b/src/rustc/middle/trans/base.rs
index d202ba7a123..8d8009ceece 100644
--- a/src/rustc/middle/trans/base.rs
+++ b/src/rustc/middle/trans/base.rs
@@ -1797,7 +1797,6 @@ fn trans_assign_op(bcx: block, ex: @ast::expr, op: ast::binop,
             arg_exprs([src]), save_in(target));
 
         ret move_val(bcx, DROP_EXISTING, lhs_res.val,
-                     // FIXME (#2704): should kind be owned?
                      {bcx: bcx, val: target, kind: owned},
                      dty);
       }
diff --git a/src/test/bench/task-perf-word-count-generic.rs b/src/test/bench/task-perf-word-count-generic.rs
index f43f27f425f..c4e51902628 100644
--- a/src/test/bench/task-perf-word-count-generic.rs
+++ b/src/test/bench/task-perf-word-count-generic.rs
@@ -77,7 +77,6 @@ mod map_reduce {
 
     type putter<K: send, V: send> = fn(K, V);
 
-    // FIXME: the first K1 parameter should probably be a - (#2599)
     type mapper<K1: send, K2: send, V: send> = fn~(K1, putter<K2, V>);
 
     type getter<V: send> = fn() -> option<V>;
diff --git a/src/test/run-pass/issue-506.rs b/src/test/run-pass/issue-506.rs
index 6fc5b5ea6eb..458a0b12698 100644
--- a/src/test/run-pass/issue-506.rs
+++ b/src/test/run-pass/issue-506.rs
@@ -1,9 +1,3 @@
-// xfail-test
-// FIXME: This test is no longer testing what it was intended to. It should
-// be testing spawning of a native function, but is actually testing
-// spawning some other function, then executing a native function.
-// #2602
-
 /*
   A reduced test case for Issue #506, provided by Rob Arnold.
 */
@@ -13,9 +7,7 @@ import task;
 
 #[abi = "cdecl"]
 native mod rustrt {
-    fn task_yield();
+    fn rust_task_allow_kill();
 }
 
-fn yield_wrap(&&_arg: ()) { rustrt::task_yield(); }
-
-fn main() { task::spawn((), yield_wrap); }
+fn main() { task::spawn(rustrt::rust_task_allow_kill); }
diff --git a/src/test/run-pass/task-comm-16.rs b/src/test/run-pass/task-comm-16.rs
index 40936ce3a06..d250b311ccc 100644
--- a/src/test/run-pass/task-comm-16.rs
+++ b/src/test/run-pass/task-comm-16.rs
@@ -52,8 +52,6 @@ fn test_tag() {
     send(ch, tag1);
     send(ch, tag2(10));
     send(ch, tag3(10, 11u8, 'A'));
-    // FIXME: Do port semantics really guarantee these happen in order?
-    // (#2605)
     let mut t1: t;
     t1 = recv(po);
     assert (t1 == tag1);