Install addon function crashes Blender


been playing with this several hours now and am getting out of ideas.

I have WinXP S2; Blender 2.62 and I am trying to instal addon for exporting to ACE format (Unreal editor).
Every time I try to install the addon via Install addon button in the User Preferences menu, the Blender crashes and keeps crashing on every startup untill I delete Blender folder in Program Files.

Same problem occurs with any script I try to install this way (eg. Povaray exporter)

So I´ve tried to not to use the button Install addon and have copied the .py OR the zip with the script (tried both options) into the Addons folder. This way the Blender doesn´t crash but I can´t see the script for activation in the Addons menu either.

I´ve tried this with several older versions of Blender as well but still no luck.

I would appreciate any ideas.