Can No Longer Upload to the Megaboard

I have a new mega 2560 which I have been getting use to & trying to write a sketch to switch relays via an Apple remote. Tonight a friend came over & helped me compile a sketch that did what I wanted. The problems started as soon as my friend left, the Arduino program crashed, so I restarted it & tried to upload the IRrecvdump sketch to retrieve some more codes from the remote but the sketch wouldn't load & I got this error

"Binary sketch size: 1,084 bytes (of a 14,336 byte maximum)
avrdude: stk500_getsync(): not in sync: resp=0x00"

I tried;

rebooting the computer
resetting the board by pressing the reset button
reloading different sketches that have worked before

but nothing worked, every time I try & load a sketch I get the same error.

Does anyone know what is causing the problem?

This:

I have a new mega 2560

does not go with this:

Binary sketch size: 1,084 bytes (of a 14,336 byte maximum)

That is not the size of a Mega. Looks to me like you picked the wrong board.

Suppose you selected the wrong target board in Tools? Could it report false capacity?

I can assure you it's the right board, the "of a 14,336 byte maximum" is new as well, it use to say something like 256,000 byte maximum" I don't remember the exact number of byte's

Shouldn't the reset button clear whatever is on the board?

In the serial monitor it keeps repeating "button state=low"

Firefox:
I can assure you it's the right board, the "of a 14,336 byte maximum" is new as well, it use to say something like 256,000 byte maximum" I don't remember the exact number of byte's

they mean the board that is selected in the IDE.

Firefox:
Shouldn't the reset button clear whatever is on the board?

so your sketch would be erased every time you reset the board?

Firefox:
In the serial monitor it keeps repeating "button state=low"

this is just the current program on the arduino that prints, it has nothing to do with the problem

GoForSmoke:
Suppose you selected the wrong target board in Tools? Could it report false capacity?

Your a genius, somehow the board setting in the software had changed, no idea how

I can onlyy think when the program has crashed it has reset the board selection, as one minute everything was fine next minute disaster

Thanks