Module Template in Theme and Language

[Roues]

1.3.2.3 - or is there a bug or am I doing something wrong.

1) Filled module translation in Tools -> Translation -> Module translations -> xx -> blockuserinfo and saved.
Than language file /modules/blockuserinfo/xx.php is created and strings on Front are translated. All OK.

2) Copied blockuserinfo.tpl from /modules/blockuserinfo to /themes/mycooltheme/modules/blockuserinfo and little edited.
On Front still everything is OK.

3) Edited module translation in Tools -> Translation -> Module translations -> xx -> blockuserinfo and saved.
Than EMPTY (44 bytes) language file /themes/mycooltheme/modules/blockuserinfo/xx.php is created and now strings on Front are NOT translated!

4) Tried to copy the /modules/blockuserinfo/xx.php to the /themes/mycooltheme/modules/blockuserinfo with replacement - strings on Front still NOT translated!

How to use the translation for module override in themes and whether it is possible at all?

[Roues]

5) Now edited module translation and saved again.
File xx.php (was copied in 4) ) replaced with EMPTY (44 bytes) language file again.