I have been playing around with my first Arduino board for the last few months and after few lessons in controlling base current through transistors and a couple ATMega328s I have all my circuit issues worked out. I ordered a replacement ATMega328 (w/ optiboot) from sparkfun, but now my Uno is not storing my sketches, I can load and run a sketch no problem, but when I remove the power and plug it back in nothing runs, if I hit the reset some of the outputs change (makes my 7-segment go to 8888) but my sketch still won’t run. I’ve tried loading some simpler sketches that I know work with no extra hardware attached and they are also not stored. I tried re-burning the bootloader using arduino 1.0 but it throws out a “did not find any usb device” error, but I’ve never messed with the a bootloader so I don’t know if I was doing that right.