>>>>BTW, our temp directory is on another drive (D). My colleague thinks, it could also be the problem.
>>>
>>>It could be if there were something particular about that drive ( i.e external drive )
>>>
>>>Jaime
>>
>>Not, it's not external. It's C partitioned.
>
>Then i don't see any particular reason for it to be the problem...

I copied the data from t:\devdata, didn't run Reindex and got an error again right after I tried the same batch (225 recs)

Error: 1103
LineNo: 605
Message: Invalid seek offset.
Procedure: runprocess
Details: 
StackLevel: 2
LineContents: if seek(m.lcStage_Patients_fk, "load_stage_employers", "cPointer_f") Time spent: 40 sec.

In addition I put SET RESOURCE OFF. My last attempt would be to try a different batch on reindexed set with temp location on the same drive. If I get this error, then I can tell that these settings only made matters worse :(