Hi guy, i've the problem when i try to upload a big sketch. I've try to upload a sketch with 28796 bytes of size and fail with this error: "avrdude: stk500_recv(): programmer is not responding". With a little sketch, i've no problem to upload it! Below some information about my Arduino and ide:
Board Model: Uno + Ethernet Shield
Ide version: 1.0
OS: Mac os X 10.6.8 (snow leopard)
Could be a bootloader problem? Some time ago I remember reading something about a bug with some bootloader version.