Hi Jason,
The problem with enumeration involves the timing and noise on the voltage supplied from USB to the MSP430. With JP7 there is adequate capacitance to maintain the necessary charge. When JP7 is removed there is no bypassing or charge reservoir on the VBUS pin of the MSP430. Every time the device tries to enumerate, charge is demanded through the L1 ferrite which eventually places the device into a brownout condition and restarts the USB connection on the MSP430. The enumeration never completes.
I resolved this issue by soldering a capacitor to the bottom side of the EVM between the JP7 connection of the USB supplied voltage and the ground terminal of J7. I used 47uF (as that is what I had handy), but 10uF should also work as that is similar to the normal capacitance when JP7 is installed.
Best regards,
Bob B