Hello,
In the last week I downloaded the Arduino 1.0 IDE, having previously been successfully using Arduino 0022. However I cannot seem to upload sketches with Arduino 1.0. I continually get an error message saying "COM8" or "COM3" already in use, regardless of which port is selected. There also seems to be an avrdude "timeout" note in the error messages.
I am running Windows XP.
Thankyou in advance for any suggestions anyone may have.
Well after reading a few forum posts regarding similar issues I tried pushing the reset button on my Mega2560 just as the sketch finished compiling and started uploading. After some intermittant success I kept trying this and now the sketches seemed to uploading ok!! I hope this continues tomorrow when I turn it on again. Very happy at the moment to have this problem sorted out 
This morning I tried out the uploading again but it seems the problem has not really gone away. However sometimes if I load a sketch using 0022 (which works ok) then immediatly load a sketch with 1.0 it seems to work?? But it is inconsistant so I still need to sort this out.
Just an update. I loaded the Arduino1.0 IDE onto my brothers computer (a laptop running XP) and installed my Mega2560 onto that computer as well. It all seemed to work perfectly..looks like the problem is with my computer...
Except ... that 0022 always works on your computer, right ? Then the problem is in 1.0 ... This seems to happen to quite a lot of people, enough to recommend staying with 0022 until 1.01 is out 
I've heard someone having succes by connecting the solderpads on the Arduino called RESET_EN, they are just above the Vin pin. Although I don't have more details about this. Maybe someone with better knowledge of the board could comment on this.
I work in Eclipse and found out that they use a completely different bootloader for the 2560 (stk500v2), this resulting in the board not resetting before uploading. I just hit the reset button before uploading, like the old days