Some question:
- how many files are there in the directory?
- what command did you use to know the dimension of the directory? Could you post the output of "ls -lsd <dir>"?
Third, a suggestion... you could try running a readonly fsck, by using the "-n" option... this will tell you if there is any problem, but remember, be careful and test this on another filesystem first! I tried on my /boot with ext3 and worked fine...