when i am looking down the server list, when i hit a certain point it crashes. i have clicked report crash file many times on the launcher but nothing has happened! this is what the crash report file says .---- Minecraft Crash Report ----
// There are four lights!

Time: 12/4/13 6:14 PM
Description: Rendering screen

java.lang.IllegalArgumentException: bad Base64 input character at 2537: 0 (decimal)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:247)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:197)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:188)
at bge.b(SourceFile:155)
at bge.a(SourceFile:130)
at bat.a(SourceFile:26)
at bay.b(SourceFile:382)
at bay.a(SourceFile:259)
at bgb.a(SourceFile:283)
at bll.b(SourceFile:851)
at azd.ad(SourceFile:780)
at azd.e(SourceFile:704)
at net.minecraft.client.main.Main.main(SourceFile:103)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Stacktrace:
at io.netty.handler.codec.base64.Base64.decode(Base64.java:247)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:197)
at io.netty.handler.codec.base64.Base64.decode(Base64.java:188)
at bge.b(SourceFile:155)
at bge.a(SourceFile:130)
at bat.a(SourceFile:26)
at bay.b(SourceFile:382)
at bay.a(SourceFile:259)
at bgb.a(SourceFile:283)

– Screen render details –
Details:
Screen name: bgb
Mouse location: Scaled: (472, 172). Absolute: (944, 319)
Screen size: Scaled: (640, 332). Absolute: (1280, 664). Scale factor of 2
Stacktrace:
at bll.b(SourceFile:851)
at azd.ad(SourceFile:780)
at azd.e(SourceFile:704)
at net.minecraft.client.main.Main.main(SourceFile:103)

– System Details –
Details:
Minecraft Version: 1.7.2
Operating System: Windows XP (x86) version 5.1
Java Version: 1.7.0_04, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
Memory: 22187408 bytes (21 MB) / 74813440 bytes (71 MB) up to 518979584 bytes (494 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.7.2
LWJGL: 2.9.0
OpenGL: AMD Radeon HD 6450 GL version 4.2.11927 Compatibility Profile Context, ATI Technologies Inc.
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: []
Current Language: Australian English (Australia)
Profiler Position: N/A (disabled)
Vec3 Pool Size: ~_ERROR~ NullPointerException: null
Anisotropic Filtering: Off (1)