Did the 'Trade' window become all wonky? If there is a deal they now report the value as -X and they tend not to accept them. They might accept them if it's a GPT deal but it's no-deal if it's flat gold. Fine. But there is a limit at which they type out that the deal is acceptable, one value (one gold away from acceptable) at which it's impossible and then the next value after that is just a negative number. So you don't really know if the negative number is beyond impossible or just a negative number.
Example; I offer to sell Askia 2 iron.
459 gold + 2 gpt = -2 value
458 gold + 2 gpt = impossible (i gather this then is -1 value)
457 gold + 2 gpt = acceptable (they will accept this)
456 gold + 2 gpt = 1 value (they will accept this)
Why is the 459g and beyond deal not listed as "impossible" to. It's somewhat annoying. I find it takes longer now to get the "best" deal, certainly so when doing all gpt deals as they then will accept a certain amount of negative values. I get the feeling that previously the "acceptable" window was larger. I wouldn't say it's a bug or anything, more of a nuisance.