Clicking noise during NO-PLAY on Raspbmc and OpenElec

Hi to everyone,

It's a lot of time that i'm looking for a solution for my problem but, every similar thred that seems to talk about it, at last talk about other.
My configuration is:
Raspberry Pi 512Mb
SD SandDisk Ultra16GB (in the supported list)
PSU 5V 1,5A (bought on ModMyPi)
TV Toshiba Regza over HDMI

The problem is a Clicking Noise Sound over HDMI during the menu navigation, but only after the first playback in Raspbmc as OpenElec.
For Example:
I power on my raspberry, during the first menu navigation the problem don't occurs, now i start to playback something and during the Movie or Music no problem occurs, but now if i stop the playback, after a little time i begin to hear this "clicking (every 2 seconds) noise".

This clicking noise appears only during the menu's navigation, instead during the playback of a Movie or some Music it's all ok.
I've tried to switch the sound on the analogic port, but the clicking noise continues on the HDMI.

I tried:
-config_hdmi_boost=4 and 7......but nothing
-to change power supply......nothing
-to use OpenElec Rbej Frodo Branch,thinking that this had the latest version of raspberry firmware.......but nothing
-to change TV with another......nothing
-to change to lower video resolutions and lower frequencies.....nothing
-to change HDMI cable........nothing
-probably others things that now i don't remember.......but NOTHING.

please......help me.
It make me crazy.

Sorry for my English,
Regards,
aeromarco!