Strange crashes upon instantiate?

Ever since I started this game, players have been experiencing crashes when they fire their weapons (hence instantiating a projectile). I haven't the foggiest why instantiating a player doesn't crash a person's browser, but that firing a projectile does!

Code (csharp):

1. //Spawn instantiation
2.  
3.  
4. var clone = Network.Instantiate(playerPrefab, pos, transform.rotation, 0);
5.  
6.  
7. //Ship instantiation
8.  
9.  
10. var clone : GameObject;
11. if (Network.peerType == NetworkPeerType.Disconnected)
12. {
13.      clone = Instantiate(projectiles[0],ps[pp].position,transform.rotation).gameObject;
14. }
15. else
16. {
17.           clone = Network.Instantiate(projectiles[0],ps[pp].position,transform.rotation,0).gameObject;
18. }
19.  
20.  
21. //In both cases, clone is used to set variables after the instantiation.
22.  

Any help?