Exchange migration using ADMT

When I run the active directory migration tool everything seems to work fine, except it doesn’t bring across the exchange user information and I get an error in the event log Catagory: LDAP operations, Event ID: 8270 Source: MSADC

LDAPeturned the error [33] Busy when importing the transaction
Can any one help me out with this I have looked every where for this error and can’t find it.