Can anyone shed any light on this problem?

I have a SSIS Package that incorporates a Script Transformation Task in the
Data Flow Task. I have deployed the Package to SQL Server and can successfull
execute the task using DTExecUI un the admin account. But when I test this
under the SQL Agent Account using runas to start DTExecUI under that account
I get an error detailed below.

at System.Number.StringToNumber(String str, NumberStyles options,
NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
at System.Number.ParseDecimal(String value, NumberStyles options,
NumberFormatInfo numfmt)
at System.Decimal.Parse(String s, NumberStyles style)
at
ScriptComponent_85acff08cc9343debad8302cf53ba20d.S criptMain.Input0_ProcessInputRow(Input0Buffer Row)
at
ScriptComponent_85acff08cc9343debad8302cf53ba20d.U serComponent.Input0_ProcessInput(Input0Buffer Buffer)
at
ScriptComponent_85acff08cc9343debad8302cf53ba20d.U serComponent.ProcessInput(Int32 InputID, PipelineBuffer Buffer)
at
Microsoft.SqlServer.Dts.Pipeline.ScriptComponentHo st.ProcessInput(Int32
inputID, PipelineBuffer buffer)

The code that causes the problem is :-

..AMOUNT = Decimal.Parse(.SIGNEDAMOUNT,
Globalization.NumberStyles.AllowLeadingSign)

The vlaue of .SIGNEDAMOUNT is "-0000000002350.55" which is the first record
in the import file. Again the only reason I get this error is the fact that
the account in which it is running has been changed to the SQL Server Agent
Account and not the admin account.

I'm about to try Service Pack 1 to see if this resolves the problem but i'd
like to know if anyone has had any similar problems or knows of a solution.

Thanks in advance,

Toby