Well, if you still hold them guilty today even though you have no specific reason to assume your experiences would be the same now, I'd call it a grudge, but let's not worry about labels if that's what's bugging you.I wouldn't call it a grudge. It was a bass that warped due to a design flaw and they were not willing to help me even if I offered to pay. But the main reason that I have not gone back to them is that they have not had any basses that have really caught my eye until this one.
Then again, you made me think. If they were not willing to fix their mess-up then, maybe I should learn my lesson and not go back there...I don't call that a grudge.
Still, it's a great looking bass.
My main point is, that was a long time ago. If they've got something that looks interesting to you now, then I'd say it's time to give them another shot unless you have a specific reason, based on current information, to suggest they'd handle things poorly again.
I'm also keeping in mind I don't know all the details of both sides of the story, so take this post FWIW, I guess.