Index on a generalized time attribute

[Frank.Offermanns@cae-gmbh.de]

Hello,

i am working with windows LDAP Version 2.2.29.

I defined an attribute:

attributetype ( myAttributeType:54 NAME ( 'LastSyncUser' )
        DESC 'Time and Date of the last Syncuser in generalized time'
        EQUALITY generalizedTimeMatch
        ORDERING generalizedTimeOrderingMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
        SINGLE-VALUE )

Now i want to index this attribute by configuring:
index   LastSyncUser    eq
Equality is all i need.

But i always get this error:
.\slapd.conf: line 88: equality index of attribute "LastSyncUser" 
disallowed

Isn't it possible to set an index on a generalized time attribute?
What can i do to fix this problem?

Thanks in advance.

Regards,
Frank Offermanns