1.6.2 crashes on launch if any mods installed

I just started trying to use Forge and I keep getting the following error report if I have any mods in the mod folder. I followed all the instructions I could find and nothing online mentions anything about how to fix it. Can anyone suggest what to do?

-- System Details --

Details:

Minecraft Version: 1.6.2

Operating System: Windows 7 (amd64) version 6.1

Java Version: 1.7.0, Oracle Corporation

Java VM Version: Java HotSpot 64-Bit Server VM (mixed mode), Oracle Corporation

Memory: 123783504 bytes (118 MB) / 376307712 bytes (358 MB) up to 1901461504 bytes (1813 MB)

JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -XX:MaxPermSize=1024m

AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used

Suspicious classes: FML is installed

IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0

FML: MCP v8.04 FML v6.2.54.739 3 mods loaded, 3 mods active

mcp{8.04} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed

FML{6.2.54.739} [Forge Mod Loader] (coremods) Unloaded->Constructed

obsidianAmourB0b{1.1.0} [b0bGary's Obsidian Armour!] (B0bGary_s_Obsidian_Tools__1.5.2_v1.1.0.zip) Unloaded

Launched Version: 1.6.2-FML6.2.54.739

LWJGL: 2.9.0

OpenGL: AMD Radeon HD 7800 Series GL version 4.2.11750 Compatibility Profile Context, ATI Technologies Inc.

Is Modded: Definitely; Client brand changed to 'fml'

Type: Client (map_client.txt)

Resource Pack: Default

Current Language: English (US)

Profiler Position: N/A (disabled)

Vec3 Pool Size: ~~ERROR~~ NullPointerException: null

You're installing a 1.5.2 mod on 1.6.2 Dont do that.