metal slug 4 sound problem?

I did try search for this, but I keep getting

"Fatal error: Allowed memory size of 16777216 bytes exhausted at (null):0 (tried to allocate 35 bytes) in /home/www/neo-geo/forums/search.php on line 951".

The problem with my Metal Slug 4 cart is that 1 in 10 times the sound works perfectly, the other 9 it is all garbled. Most of the time when I boot I see corrupt graphics on the screen before I get the playmore symbol. I am using a Neo Geo 6 slot cabinet. I've cleaned all connectors and all carts plugged in it. Any ideas why I get this strange behaviour?

After trying quite a few things, I discovered if I start playing while the corrupt graphics are on the screen I get stuffed sound. But, if I wait a few seconds for the playmore symbol, then I get good sound. Is this a known bug with this game?

With my MVS Metal Slug 4 cart(new kit)..The first time it reaches this game in my US BIOS 4 slot motherboard...when the screen shows the parental advisory it's garbled..second time around the demo loop it's fine though I have started a game during the first garbled parental advisory screen with no problems.

Metal Slug 4 will not work right in my Candy Cab with it's "old"Uni Bios chip in the 4 slot mother board.
The sound totally goes out etc.

When I first put Metal Slug 4 in my 4 slot mother board/Candy Cab it went in to tight..then I tried it in Big Reds 4 slot mother board and it felt to tight too.
IMO the cases these were made in are crap..the PCBs are too tight in them..
With cart tight in the Big Reds 4 slot mother board I was having sound problems.

I opened the cart up and cleaned the contacts (before the first try)and cleaned them with light sand paper and alcohol.
Still this cart did not feel right going in the mobos..So I opened it and shaved several parts of the inner case to get the pcbs to slightly wobble whereas they are not so tight in the case.
I do this shaving with a lot of carts as I want my games to have a "slight" pcb wobble.
After that it slides in the Big Reds 4 slot mother board smoothly and works perfectly.
I see a warping in carts pcbs when they are to tight so that can cause all kinds of problems..

My Metal Slug 4 (new and complete) is the only game I have in an odd casing. Did SNK run out of their usual cart casings for MS4?

Mine is in an Odd casing too....None of my other MVS cases have the type of grain/feel that this one does.

Black Case with a gritty type of a grainy feel to it...

Yeah the slug 4 kit is different in a few ways.

matte black case with a heavier feel than the normal glossy black case

non-sticker move sticker, just paper with square edges, not laminated either

Only slug 4 and kof01 have

an odd serial number system

and an odd box

heavy pink bubble wrap