avrdude: stk500_getsync(): not in sync: resp=0x00

I'm new to all this micro controller stuffs, I'm working with arduino Duemilanove based Rf controlled bot.But i got these error message
avrdude: stk500_getsync(): not in sync: resp=0x00
I have no idea how to solve this...I brought a new kit checked all the ports and usb cable ,everything alright .
Everything was going fine and suddenly i got this issue with the uploading and my bot doesn't works even though it receives signal from the transmitter.
Somebody please tell wat to do????

You get that message when your PC cannot communicate with the arduino. Unfortunately,
there are 1001 reasons why you might get that. The unreliable nature of communications
is the arduino's biggest shortcoming.

Any solutions you wanna give....other than checking correct ports and and board ???
what about replacing the Atmega 328 Chip??

Well replacing the chip is not a realistic option for most devices.
There is a long checklist here of things you can try to check.
Get a different arduino and see if that works.
Try a different computer.

ya...thanks a lot ...let me try changing computer...

That´s THE problem EVERBODY gets. Supposedly due to communications breakdown. Try shortening your wiring.

Are you trying to upload over RF? That doesn't seem to be working very well.

I tend to suspect that a lot of these are due to Windows not making clear WHICH comN port has your arduino connected to it. The IDE ends up talking to an empty port, which of course does not respond...

Still I'm getting the same error message frens....nothing seems to workout the prblm..

Have you checked the physical connection? Has the USB cable been used elsewhere with out problems? When plugging in do you see the Arduino in device manager on Windows?

yes I've checked physical connections tried with some other usb too...device manager also showing the correct port,but output doesn't seems to change.

Could be the baud rate setting...
Goto File->Pref... in the Arduino IDE and set verbose mode for uploading so you will see what baud rate is being used.
Maybe your chip has a bootloader that is using 115200 instead of 57600 or the other way around.
Edit boards.txt (find the board you are using) and change its baud rate to 115200 or 57600, save it, restart the IDE and try again.

Hi folks,

I'm also getting this error when trying to connect to an Uno. I'm using a Windows Vista machine with the Arduino IDE already installed and previously working on a Mega 2560. Given that it worked with the Mega jsut a week ago, I know that the PC, serial port and lead are all OK. The Uno is new and works on other machines. Very curious.

I'll post more when I know more.

Given that it worked with the Mega jsut a week ago, I know that the PC, serial port and lead are all OK.

Doesn't windows create new serial ports for new usb/serial converters?

Good point.

Thanks; I'll pay closer attention to Device Manager