There is a weird happening occured involving Relinquished, Premature Burial, one trap card and one monster card. This error happened once to me (I'm not that dumb to repeat it if I can help it or if I know what cause it) and it was in a Match Duel when I'm facing Kaiba in Kaiba The Revenge game.

This error occured by the following actions (in order of events):
1. You have a Relinquished on your side of the battlefield (Relinquished will always be face up, never face down).
2. There is one monster in Kaiba's side of field that was 'revived' by the effect of Premature Burial, and therefore it's on face up position.
3. There is at least one trap card on your hand.
4. You activated Relinquished's effect to absorb the monster that was equipped with Premature Burial. What will happen? You get the monster? NOT. The monster and Premature Burial will be destroyed. Why? I'm assuming coz the monster was considered as 'dead' or something.
5. Afterward, since Relinquished ATK/DEF become 0, you decided to place a trap card to protect it from being destroyed. Now, what will happen to the trap card? It become Relinquished's equip card, replacing the place where the previous Premature Burial's monster should be if it's not destroyed. Weird, I know.
6. Thanks to the weird incident, the trap card will not be usable. There is a question of 'Do you wish to activate a quick spell or trap card?' appeared when the condition to activate the trap card fulfilled but even if you say 'Yes', you still can't activate the trap card.
7. The symbol of 'equip' will appear on top of Relinquished if you hover your mouse on top of your trap card or the other way around. Also, you can't activate Relinquished's effect to absorb another monster on Kaiba's field because the game think you've already got 'something' that Relinquished absorbed. And, when Relinquished was attacked, the trap card will be destroyed (since it ATK/DEF was 0, ANYTHING will destroy Relinquished), just like what would happened if it was a monster card. Really weird.

The question is, what's the actual rule of the game that caused it to be 'confused' like this? Maybe it's because the game didn't have the 'right' rule of what supposed to be happened when Relinquished's effect combined with Premature Burial's effect or maybe it was because of something else.