Connect betwwen ATMega8U2 - ATMeaga5260

Both Oscilators fine I see echo on terminal. I steel can program from AVR ISP v3.2 both chips: stk500boot_v2_mega2560.hex or temp hex (2560 chip works good) from ard. ide and Arduino-usbserial-mega.hex vyrifing ok. When erase 2560 (AVR ISP) leds down. When load bootloader led13 blinking 10Hz.

But cant program from IDE: write bootloader - log "isp not in sync" write sketch - tx and rx blinking1-3 times per some seconds (10-50) ...and finaly it log "timeout".

Can u help me?

Serial examples loaded with AVR ISP work fine.

Looking at another same! problems, i think it software (hardware in mega8U2) problem, if it is, will wait for upgrades.