This still seems to be occuring in version 0.5.1.1.
Crash log:
java.lang.StringIndexOutOfBoundsException: String index out of range: 1
at java.lang.String.substring(String.java:1963)
at yc.redirect$zzm000$redirect3(SourceFile:593)
at yc.a(SourceFile:60)
at da.g(SourceFile:134)
at da.e(SourceFile:112)
at net.minecraft.client.Minecraft.k(SourceFile:1299)
at net.minecraft.client.Minecraft.run(SourceFile:754)
at java.lang.Thread.run(Thread.java:748)
This still seems to be occuring in version 0.5.1.1.
Crash log: