Great news! I don't want to rain on the parade, but I'm still a little concerned because we don't know why attaching the LCD has spontaneously fixed the problem. If it works it works, I guess, but it would still be good to figure out what's going on.
I wonder, when you removed the LCD originally, did you also remove the 1k pull up resistor on pin d3 of core j15 (shown here: http://ucapps.de/mbhp/mbhp_lcd_4bit_mios8.pdf ). Not having that resistor stuffed has been known to cause BOR style reset patterns similar to what (I think) was going on with your core.
Anyway, the patch can be changed by sending a midi program change message. Most keyboard style midi controllers have this hard wired to generic + and - buttons. If you want to change a bank, send CC#0.
Glad you got it working!