Hi,last week i bought Original Splinter Cell Double Agent game.
During the installation i found something strange,it never asked for CD Key eventhough i had a SC-DA Activation Key note packed along with the CD
After the installation when i try to launch the game,it responds properly till the difficulty setting menu.Afterwhich the loading screen for the first mission appears and the game crashes.
The following is the error message which i receive everytime.

Assertion Failed : TopChunk==Null[file:\unMem.cpp][line:54]

PFB my system properties

Processor : Intel Core 2 Duo CPU Processor E4500 @ 2.20GHz
Ram : 1GB
System Type : 32-Bit OS
Graphics Card : Nvidia 9500GT
OS : Vista (Service Pack 2)

Kindly provide any assistance so that i can play the game