Sometimes, the text when you have any language that has the bigger letters on gets very buggy and barely readable. This bug happens with any texture pack (including default). I don't think you have to do something particular to reproduce this bug. The console did not say anything special. The only Java exception I saw was:
Client> java.io.IOException: Stream Closed
Client> at java.io.RandomAccessFile.seek(Native Method)
Client> at adu.a(SourceFile:308)
Client> at adu.a(SourceFile:251)
Client> at adv.close(SourceFile:232)
Client> at java.util.zip.DeflaterOutputStream.close(Unknown Source)
Client> at java.io.FilterOutputStream.close(Unknown Source)
Client> at adx.a(SourceFile:140)
Client> at adx.c(SourceFile:128)
Client> at amj.b(SourceFile:30)
Client> at amj.run(SourceFile:23)
Client> at java.lang.Thread.run(Unknown Source)
I do not think this exception has anything to do with the buggy text. It (the exception) happens every time I run the snapshots, I think.