gitk: bad text index "a:...."

[max630]

bad text index "a:1981"
bad text index "a:1981"
while executing
"$w image configure a:$ix -image tri-dn"
(procedure "treeopendir" line 6)
invoked from within
"treeopendir $w $dir"
(procedure "treeopendir_rec" line 9)
invoked from within
"treeopendir_rec $cflist $dir"
(procedure "locate_changed" line 20)
invoked from within
"locate_changed locate_efile {} write"
(procedure "setfilelist" line 12)
invoked from within
"setfilelist $id"
(procedure "gettree" line 26)
invoked from within
"gettree $id"
(procedure "selectline" line 162)
invoked from within
"selectline [rowofcommit $id] 1"
(procedure "gotocommit" line 29)
invoked from within
"gotocommit"
(command bound to event)