submit multiple HCM Extract from OIC

When I submit multiple HCM extracts from an OIC flow using a while loop for incrementing (1 corresponds to extract 1, 2 to Extract 2 and so on), sometimes I get a SOAP fault on flowinstanceID call (which basically checks if the extract has completed). The HCM extracts however do not fails and successfully run to completion.

Has anyone faced this issue and how did you get around it?

Thanks,

Aloka