Issue in Script task

Hi,

I have two DFTs which runs in parallel. Both of them has a script task which takes the records and increments value of local variable and finally assigns to one package variable.

in First DFT I have i1 and 2nd DFT, I have i2.

1st DFT:

int cnt;

Cnt++;

i1=Cnt;

2nd DFT:

int cnt;

Cnt++;

i2=Cnt;

When both of them runs in parallel, its throwing following issue:

[Script Component [80]] Error: System.Runtime.InteropServices.COMException (0xC0010009): Exception from HRESULT: 0xC0010009
   at Microsoft.SqlServer.Dts.Pipeline.ScriptComponentHost.HandleUserException(Exception e)
   at Microsoft.SqlServer.Dts.Pipeline.ScriptComponentHost.PostExecute()
   at Microsoft.SqlServer.Dts.Pipeline.ManagedComponentHost.HostPostExecute(IDTSManagedComponentWrapper100 wrapper)

[SSIS.Pipeline] Error: Script Component failed the post-execute phase and returned error code 0xC0010009.

Any idea?

Porus