[0.6.1] Stacked items not appearing when dropped

[Verodoxys]

Title: [0.6.1] Stacked items not appearing when dropped

Version: 0.5.1

OS: Windows 7

Java Version: Recommended Version 7 Update 17

Description of Problem:

I think the title says all; Items dropped in stacks occasionally fail to appear on the ground, resulting in total loss of the stack. This appears in both SP and MP.

This has been quite devastating to me whilst breaking my chests by accident. Dropping tools and single items is safe.

(The Tekkit Lite Version will say '0.5.1'; Please note that this is an 0.6.1 bug. It won't let me select 0.6.1.)

Error Messages:

N/A

Error Log:

N/A