diff -r 11c290b5edf9 src/syscall.cpp
--- a/src/syscall.cpp	Wed Nov 09 14:50:18 2011 +0100
+++ b/src/syscall.cpp	Wed Nov 09 15:07:03 2011 +0100
@@ -244,11 +244,13 @@
     }
     Pd *pd = static_cast<Pd *>(cap.obj());
 
-    if (EXPECT_FALSE (r->utcb() >= USER_ADDR || r->utcb() & PAGE_MASK || !pd->insert_utcb (r->utcb()))) {
+    if (EXPECT_FALSE (r->utcb() >= USER_ADDR || r->utcb() & PAGE_MASK)) {
         trace (TRACE_ERROR, "%s: Invalid UTCB address (%#lx)", __func__, r->utcb());
         sys_finish<Sys_regs::BAD_PAR>();
     }
 
+    pd->insert_utcb (r->utcb());
+
     Ec *ec = new Ec (Pd::current, r->sel(), pd, r->flags() & 1 ? static_cast<void (*)()>(send_msg<ret_user_iret>) : nullptr, r->cpu(), r->evt(), r->utcb(), r->esp());
 
     if (!Space_obj::insert_root (ec)) {