You can also try fine sandpaper, or a metal nail file. These work well for me. Be sure to clean off any filings before use, of course.
FWIW, I'm sure your Arcade Card is fine.
If you still have problems after further cleaning/sanding the issue is your Kisado.
I have a Kisado that one day became a victim of the same problem that plagues toaster NESes: after years of inserting and removing carts, the contact pins eventually bend to a position where they don't make contact properly with carts anymore. Manifestations of this problem are exactly what you describe in addition to you being able to insert and remove carts from the Kisado more easily than you should. Unlike the NES, where you can simply replace the 72-pin connector inside the console with a more robust version, I don't know of any similar fix for the Kisado. I've never tried to take apart a Kisado but from previous inspection I recall determining such an operation would be extremely messy. I think the thing is just glued together.
My solution was to take a large matchbox and cut a piece of cardboard from the thin outer casing with the exact same dimensions as a HuCard. Make sure the cardboard is less than 1mm thick. Insert your cart into the Kisado so that the cardboard is underneath and flush with the cart on all sides. This will lift the cart just enough to make perfect contact with the pins in the Kisado.
As an aside, this technique can also be used on Kisados that don't have the "NES syndrome". This makes the contact between the converter and the cart much more reliable and eliminates the issues that occur when you bump or nudge the converter while playing. In fact, you can use a converter as a mini diving board in the middle of a game without your game crapping out with this technique if you so desired.
This solution is not elegant, but it is functional and works well.