[Exim] helo_verify and EHLO containing *domain* name?

Since one of the conclusions on my recent thread on "virus" policies was
that even simple HELO verification might stop a large proportion of all
virus messages, I've tried enabling helo_verify on our MX. And indeed,
it does seem to stop a lot of junk. However, there is one problem;
messages from genuine servers is sometimes stopped with

2004-03-10 02:37:44 rejected EHLO from dmz158.dnv.com (dnv.com)
[193.212.132.158]

(from the reject log.) The problem appears to be that the EHLO contains
a domain name rather than a host. Shouldn't this be accepted? - One part
of the Exim spec seems to suggest that it should, another doesn't
mention domain name at all. If not, is there any way around this problem
- besides disabling helo_verify for some or all servers?

Exim version is 3.34. I *still* haven't upgraded, based on the simple
prinsiple of "if it's not broken, don't fix it" (and my setup basically
*works*, although I need to adjust policy checks etc. now and then.)

- Toralf