I can't wait to hear Ian's comment on this.
And I'm guessing I'll probably agree with him pretty much 100% on this.
Hey Nintendo - Free Advice:
Create a free, downloadable Metroid: Other M channel with gameplay videos. Include a bug fix program in this channel. If you've got an effected save file, you load this Other M: Demo Channel, select the "Fix Save File" option, it opens the save file in your memory, fixes the locked door, then re-saves it. Easy-peasy.