fair enough, 
Let me tell you what happens when I try to upload:
- Compilation
- says uploading
- the robot control board resets; by that I mean:
-RX line flashes a couple times fast
- LCD screen goes blank
- immediately after that the current sketch is operational again and the IDE is stuck at "uploading..." for a little while more
- This output is resulted:
################################################
avrdude: Version 5.11, compiled on Sep 2 2011 at 19:38:36
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2009 Joerg Wunsch
System wide configuration file is "C:\Program Files (x86)\Arduino\hardware/tools/avr/etc/avrdude.conf"
Using Port : \.\COM6
Using Programmer : avr109
Overriding Baud Rate : 57600
AVR Part : ATmega32U4
Chip Erase delay : 9000 us
PAGEL : PD7
BS2 : PA0
RESET disposition : dedicated
RETRY pulse : SCK
serial program mode : yes
parallel program mode : yes
Timeout : 200
StabDelay : 100
CmdexeDelay : 25
SyncLoops : 32
ByteDelay : 0
PollIndex : 3
PollValue : 0x53
Memory Detail :
###################################
and this:
###################################
Found programmer: Id = "†ÿ("; type = a
Software Version = E.
...
avrdude: error: buffered memory access not supported. Maybe it isn't
a butterfly/AVR109 but a AVR910 device?
###################################
What I tried: Pressing reset before upload and on compilation, pressing reset before the usb cable is plugged, fixing the preferences.txt because somehow it was not reflecting the current options selected on the IDE (wrong board, wrong com etc.)
So do you think any of this is helpful?
thanks !