Multiple inheritance is generally a bad thing, yes. Interfaces are the exception (according to Andre LaMothe). In fact, one of the main benefits of using interfaces is that you can have multiple inheritance without much trouble, which allows for cleaner class heirarchies. For example:

Below is a generic class heirarchy.

Object
   Character
      Enemy
      Player
   Item
      Shield
      Weapon
      Ammo
      Health

Problem: Some items can be held in an inventory, others are simply collected.

Solution: Make a seperate class for inventory items

Object
   Character
      Enemy
      Player
   NormalItem
      Shield
      Food
   InventoryItem
      Weapon
      Ammo
      Gem

Problem: Some inventory items can be used at will, others are just there to collect or are automatically used when needed

Solution: Make a seperate class for usable inventory items

Object
   Character
      Enemy
      Player
   NormalItem
      Shield
      Food
   InventoryItem
      Weapon
   UsableInventoryItem
      Ammo
      Gem

This leaves us with an increasingly complex structure. Eventually, you're going to have an item that belongs in more than one group (needs methods or data from more than one base class).

Here's the same heirarchy using interfaces.

IInventoryItem
IUsableItem

Object
   Character
      Enemy
      Player
   Item
      Shield : IUsableItem
      Food
      Weapon : IUsableItem, IInventoryItem
      Ammo : IInventoryItem
      Gem

Maybe not the best example. I'll try to use something from my actual code (when I get that far).