Error Mass Operand Update

Hi All Expert,

   I am having a small issue but I am not successful to regenerate this case.

I am using an BAPI to update operand "BAPI_UTILINSTALLATION_CHANFACT". With this BAPI I am updating 2 Quantity and 4 Demand operand at the same time.

Problem I am having is when I updated the operand for single installation it's work fine but when I am updating the operand in a loop for more than 10 K records I am getting 2 weird error.

AH   - 418  - Enter dates that do not overlap

AH  -  495  - Entry for date &1 already exists

While there is no issue in data. it's seems when we are updating for multiple records/installations some buffering issue or something like that.

Any Idea appreciated.....

Thanks

Atul Joshi