RSS notification bug

I use tkabber 0.10.0 (TCL/Tk 8.4.13) on win32.
I`m subscribed to mail.ru-im-transport mrim.jabber.ru. This transport notifies me of new mailbox messages.
Since 0.10-beta2 (or maybe earlier) the error happens when the notify arrives and the window where new messages` headers show is not the tab but the separate window.
Here`s the error message.

Hook process_message_hook failed
Procedure ::plugins::headlines::process_message returned code 1
image "browser/headline" doesn't exist
image "browser/headline" doesn't exist
while executing
"$path configure $realopt $value"
(procedure "Widget::_test_tkresource" line 7)
invoked from within
"$Widget::_optiontype($type) $option $value [lindex $optdesc 3]"
(procedure "Widget::init" line 69)
invoked from within
"Widget::init Tree::Node $path.$node $args"
(procedure "Tree::insert" line 15)
invoked from within
"Tree::insert .headlines.tree end root 449FE9C27E7CFF89203BA1AA076CF17F -text mrim.jabber.ru -open 1 -image browser/headline -font font -fill MidnightB..."
("eval" body line 1)
invoked from within
"eval [linsert $args 0 Tree::$cmd .headlines.tree]"
(procedure ".headlines.tree" line 1)
invoked from within
"$tw insert end root $fnode -text [string map [list "\n" " "] $text] -open 1 -image browser/headline -font $font -fill $options(seencolor) -data [li..."
(procedure "show" line 67)
invoked from within
"show $connid $from $type $subject $body $thread $priority $x"
("headline" arm line 2)
invoked from within
"switch -- $type {
headline {
show $connid $from $type $subject $body $thread $priority $x
return stop
}
}"
(procedure "::plugins::headlines::process_message" line 2)
invoked from within
"::plugins::headlines::process_message 1 mrim.jabber.ru 8538544 headline 1 {У вас есть непрочитанные письма} {Непрочи..."
("eval" body line 1)
invoked from within
"eval $func $args "