I updated my Minecraft and installed Forge 6.5.0.470 after the release of RedPower 2 (Whooo!) but I've noticed some bugs concerning enchantment tables.
1.4.6 added enchanted books that allow for exclusive enchantments to be applied to items. For example, using an anvil lets you combine any tool that has durability with an Unbreaking enchanted book. This allows you to get, for example, a sword with Unbreaking. This is supposed to be a specific anvil function, however, with Forge installed, one can get Unbreaking swords even in an enchanting table. Similarly it is also possible to get an Axe with Sharpness, Smite, or Bane of Arthropods in the vanilla enchanting table, which is another example of an enchanted book-exclusive enchant for a specific item.
Steps to reproduce:
Install Minecraft Forge 6.5.0.470
Enchant tools that have book-specific enchants (Such as Unbreaking on Swords or Armor)
Sometimes you'll receive those book-specific enchants, even from the normal enchanting table
Another thing worth noting that when using RedPower, it's possible to enchant a sword that has both Sharpness and Disjunction at the enchanting table, even though it's impossible to manufacture such an item at the anvil. This could be a RP2 bug, though.