old lacie d2 firewire hard drive not mounting on macbook air

i have an old lacie d2 firewire hard drive (circa 2006) which i have tried to use with my macbook air (mid 2011) via the hd's usb 2.0 port to my mac's usb port. however the mba is not reading the hd, the hd goes on but the mba will not mount it and no trace of it can be found anywhere on the mba. however the cursor goes a little bit wobbly on the mba but that is all. any idea on how i can get the mba to read the lacie hd? any help would be appreciated!