I had lots of problems with my bleepbloop usb cart in the past. Somehow my saved songs got lost. So I tried to flash the cart with an more up to date LSDJ. But all I got was lots of error messages in GBCFLSH. Nothing worked. So I tried the windows tool with parallels, but it did not work either. So I thought my cart might be damaged.
I gave it a last try on my girlfriends iMac and it suddenly worked fine. I now could read RAM and FLASH and upload the new version of LSDJ which seems to work fine, too.
So what might be wrong with my MacBook? I got a White Macbook Unibody (late 2009) and Snow 10.6.3. My girlfriend gots an iMac 21,5“ (same SL version as mine).