Keyboard space bar not working

Hi,

totally novice and new to mac here,my keyboard space bar working fine.. but with in an time span of 3 hrs something went wrong and now whenever i press it it gives thet error sound.But it works normal when i keep the shift key pressed.

so far which i can recollect the settings i have working before this event is:

1)enabled fast user switching.

2) changed the computer name

3) installed transmission and was dowloading 2 files

4) installled sun download manager and downloading solaris

5) enabled "announce the time" in clock preferences

my keyboard firmware update is uptodate
EFI firmware is 1.1 and up to date
thts all...

can anyone help?

Message was edited by: ashokdurai