Slug 5 MVS distorted sound

I use the Metal Slug 5 MVs cart on a one slot board with supergun and on a consolisd two slot. Both boards are working perfectly with other games, but with Slug 5 I get distorted sound. IS this normal for MEtal Slug 5?? Or is my Slug 5 MVS cart just a tad fecked?? Appreciate any help guys!!
Oh and youse are right, Slug 5 MVS won't work with any Phantom, be it the blue or the previous model, I tried it

is it a black cart with blue letters on the sticker? better yet ... can you post pics of the pcbs?

giving the contacts a good cleaning might just do the trick.
there's sometimes some stuff from production on the contacts that can cause those kinda probs, until it's scrubbed off.

Cheers for the advice folks!! Will try cleaning the contacts.
And supergoose, yes, it is a black cart with blue letters on the sticker. Why, is it common with this cart?? I'd post pics, but unfortunately do not have a camera
But let me know if you anything lese re this. Meantime I shall try cleaning contacts. Ta

would have been interested in pics of the boot's pcbs, but you seem to have a legit cart.

Oh mate, I do not do boots!!! I am totally against them ever since I got in touch with you know who when I was new to ebay and the neo scene!!!
Anyways, the cart is legit as it was purchased from the very neoStore!!
Hope thats clear