Problem with keyboard connected

got a small problem, whenever i start up my megadrum with the keyboard connected i get the menu asking me to choose the frequency, 16mhz etc. except none of the buttons do anything other than (i think) left, which when i press it bring up the "Send Sysex now" message.
Without the keyboard attatched it works fine and brings up the blank velocity bars.
it seems to me like maybe the buttons aren't the right type, or broken, from looking round some threads it seems like it's detecting that i'm holding the left button so it bring up the bootload menu?
I've double checked that i've wired everything right and now i'm stuck. Any help would be much appreciated, as it's starting to give me a headache
Without the keyboard attatched it works fine and brings up the blank velocity bars.
it seems to me like maybe the buttons aren't the right type, or broken, from looking round some threads it seems like it's detecting that i'm holding the left button so it bring up the bootload menu?
I've double checked that i've wired everything right and now i'm stuck. Any help would be much appreciated, as it's starting to give me a headache
