DBEngineError $2749 on TQuery.Next

Hi

I hope some body can help, here is the problem ...

I am looping through a SQL server 6.5 dataset to populate a local paradox
tabe, this data set will in turn be used to perform a large ad complex print
run. What I have found is when the TQuery.NEXT is called from within a While
NOT TQuery.EOF do loop I get the following error :
EDBEngineError $2749.
The same error can be created if you call TQuery.Last followed by
TQuery.First

What does it mean and secondly how do I correct it?

I have looked at :

TI3212 - No longer available
TI2733 - No longer available
TI2814
TI3160

Thanks for any comments,

Gavin