It's possible the card might be bad.
Freeze ups usally mean overheating, check the chips on the card for blackened spots, and also put your finger on the main chip to see if it's getting really hot, after it's running for a while.
An obstacle is something you see when you take your eyes off your goal.
OR, Try a fan on the card to see if that is the case. Take a small house fan and point it in on the card. If it helps then yes the card is overheating. If not, then check memory ranges. For good measure make sure that the Monster card is not right next to another device in the mem ranges. This could also cause lockups. If it is overheating call 1-541-967-2450.
If you are in an area where you are not able to dial a USA 1-800 number, you may dial 541-967-2450. When calling, there will be an option for getting sales or RMA information. The direct line to Customer Service is 408-325-7000, and their fax number is 408-325-7408.
You may also send email to firstname.lastname@example.org.