[marlz]

Woah! You've had the disappearing glitch too?

I also got it in Slig Barracks in Block 4, part 2.

Whenever I tried to throw a grenade,

1. The Flying Slig on the screen disappeared and reappeared black and pixelated in place of Abe, who also disappeared.
2. When Abe disappears, I lose all control of him, so I can't stop the grenade from blowing me up. If he is crouching, however, the grenade doesn't beep at all and Abe occasionally explodes without warning.
3. After I leave Block 4, whenever I try to throw a grenade, the game freezes for a few seconds.

EDIT: This problem remains in my save file until I leave Slig Barracks. If you do Block 4 before Blocks 1, 2, and 3 and this glitch occurs, it becomes impossible to progress.
It was extremely funny though.