Hi Korakurider&Yoshiki,

Good, I modified:

#: Language name as you'd like it to appear in the Languages menu
msgid "Language-Name"
msgstr "Spanish"

#: Scale to apply to font size (2 for twice as large)
msgid "Font-Scale"
msgstr "1"

#: Directionality of language
msgid "Language-Direction"
msgstr "LTR"

#: Use this if you do not want any of the text to be bolded, for legibility
msgid "Suppress-Bold"
msgstr "false"

#: Font to use on a Windows system
msgid "Win-Font"
msgstr ""

#: Font to use on a Mac system
msgid "Mac-Font"
msgstr ""

#: Font to use on a Linux system
msgid "Linux-Font"
msgstr ""

at es.po (etoys.mo also) and etoys.pot and now I get a correct translation. Thanks Korakurider!.
But I go on with pangoRender problems.
1.- I open etoys-dev-4.0
2.- I put Preferences / pangoRenderer Off
3.- if I test differents languages there are not problems, but if I put pangoRenderer On (as deffault), then some windows shows stranges bounds (as the screenshot I attach).
Nobody more?. I do not modify etoys-dev-4.0 at all!

Sorry very much if the problem is only in my machine.