[Typo3] Problem on create new extenion: t3lib_extMgm::addPItoST43(...)

[Raul Romero Garcia]

Hi list,

When I has create a FrontEnd extension as includeLib that uses
t3lib_extMgm::addPItoST43(...) in its ext_localconf.php, run right.

But when I install another extension that uses
t3lib_extMgm::addPItoST43(...) in its ext_localconf.php, only one of
this extension run right. 

I think that the t3lib_extMgm::addPItoST43(...) add the extension
content at page.99, but if two extensions uses this feature, only one
(the last) append its content at page.99....

is not possible to do use t3lib_extMgm::addPItoST43, but without
overwrite page.99 ?

Thanks for your answers (and sorry for my bad english)