Rowcount is not being returned properly

I am using rdo to connect with microsoft access 7.0. After opening a recordset in rdDynaSet mode i move the record pointer to the last record and the first record simultaneously. If the recordset contains more records i.e about 100-12- records after the movelast and the movefirst statement i am not able to get the rowcount properly. The rowcount is returned as -1. Can you suggest me some solution to this problem. I am using the database driver for Microsoft Access Driver (*.mdb). The code returns the value properly if the no of records is less

Rowcount does not always return correct values.I use the the EOF/BOF property of the recordset instead to traverse through the recordset.