It's not uncommon to see small panel shaped antennas sold with claims of great gain, UHF/VHF & FM capability. The really bad ones also claim fantastic mileage, 100 or more miles.
Then the reality sets in. The basic antenna element is little better than the UHF loop on a rabbit ear style indoor antenna. I honestly don't know if that's the design used in the antenna you're using but your description strongly suggests that you have an antenna with modest UHF capability and little if any VHF performance.
If you/re committed to making an attic installation work, try an Antennacraft Y10713 (if it will fit and aim correctly). It's a large High-VHF antenna, designed to receive real channels 7 through 13. The two signals you're having a hard time with are broadcast on real CH-8 & CH-10 which a UHF antenna is not going to do well with.
If the Y10713 can't fit, then consider the Y5713. In either case the antenna needs to point west. The down-lead terminals are toward the rear of the antenna in this design.
You'll need to use a UHF/VHF signal combiner to merge the signal from your existing antenna with the new H-VHF antenna. The Radio Shack #15-2586
http://www.radioshack.com/product/in...ductId=2103923 is preferred in this case because it can pass power for the UHF antenna's amplifier circuit.
If we were neighbors, you'd see an Antennas Direct DB4e and an Antennacraft Y10713 on my roof.