Opning chests form a ladder ( while moving down )

[BigShinyToys]

I walkes a cross the machenical floor ( where the Lift is powered / controlled form ) to a ladder that allowes me to enert the main floor of the House . After walking over i climbed down the Ladder on the way down i rembered i was looking for a map so while still on the ladder going down i right clicked a chest near by. After that the game saved chunks then displayed an error screen for like a second then crashed.

I Have Minecraft 1.7.3
With Modloader 1.7.3
mod_thx_helicopter_beta_1.7.3_v008.zip ( im 100% shoure this mod is NOT the probblem as it is a packed mod that alters no base classes and has nothing to do with chests or ladders )
BTW 2.66

So What I think is this is a "Mojang Bug" but as youre mod has somthing simlar to a ladder ( the rope ) I thought you should Know about it. And if this is a "Mojang Bug" is there any chance you could fix it .

I have reported this to Notch via Twitter but i dought i will get a reply.

Thank you for youre time
BigShinyToys

[FlowerChild]

Please don't report bugs in vanilla Minecraft. There's a ton of them.