[imp] "Invalid Address" in From field in mailbox, but not message view

[Rob Rosenfeld]

I am running CVS Horde and IMP from approximately a week ago.  I have 
started receiving messages from users at a company whose messages have 
the following From: header format:

From: "Last, First \(Exchange\)" <user at domain.com>

In the mailbox view (after clicking Inbox, for example) their address 
shows up as "Invalid Address".  When I view the message by clicking on 
the subject, the message view displays the address as

From: "Last, First (Exchange)" <user at domain.com>

The "\" escaping the parens are mucking it up.  Not sure if that 
violates email specifications, but is there a way I can fix this?  I see 
two places in mailbox.php that will substitute "Invalid Address".  Think 
this one is causing it around line 551.  I tried IMP::bareAddress(), but 
don't really understand what's going on at that point.

    /* Format the from header. */
    if (isset($h->from)) {
        $from_adr = IMP::bareAddress($h->from);
        $from_ob = array_shift(imap_rfc822_parse_adrlist($h->from, ''));
        if (is_null($from_adr)) {
            $msg['from'] = _("Invalid Address");
            $showfromlink = false;

Thanks,
Rob