Not easy-to-understand error message from icc in AsyncCall.cc

Hi all,
  maybe someone with a deeper understanding of c++ than me could check
out this error?
See
http://build.squid-cache.org/job/3.HEAD-amd64-CentOs-icc/47/console

The erorr is:
../../../src/base/AsyncCall.cc(10): error #1931: explicit
specialization of member "InstanceId<Class>::Prefix [with
Class=AsyncCall]" must precede its first use (at line 10)
  template< > std::ostream & InstanceId<AsyncCall>
::print(std::ostream &os) const { return os << Prefix << value; }
template< > const char *InstanceId<AsyncCall> ::Prefix = "call";
template< > InstanceId<AsyncCall> ::Value InstanceId<AsyncCall> ::Last
= 0;

The offending line is:
InstanceIdDefinitions(AsyncCall, "call");

InstandceIdDefinitions is a helper macro defined in src/base/InstanceId.h

Thanks!

-- 
    /kinkie