To back Ravetown up regarding the Vaul Hunter Relic, the PC crowd have tested a +10,000 chance to find rare loot Vaul Hunter Relic and it has yielded no result. To put it to an end, it's glitched. End of discussion.
They tested the vault hunter relic on Terramorphous. In a really bad test. It appears Terra drops a set number of purples each time, basically.
They didn't really do any thorough testing (not to mention the Vault Hunter relic effect might not actually be based on what the number is set to, since it only comes in 5% so might just result in a bit being flipped elsewhere when in use)..
I'm not saying it *isn't* glitched, but the testing they did, as described, really wasn't any sort of useful test either way.