Final Cut Pro 7 does not launch with DisplayLink USB 3 to HMDI Connected

I get this error with USB3-HDMI-DVI DisplayLink connected into the 2013 iMac with 10.8.4 on launching FCP 7:

“Final Cut Pro requires that your system have 128 mb of VRAM, your system has 0 VRAM…”

Won’t let me launch FCP at all.

I have 2GB VRAM. All other video production software (Media Composer, Adobe, etc. ) works fine. FCP will launch with DisplayLink unplugged. I have latest drivers. Just trying to use as second desktop monitor. I was singing this products praises until I found this error (I use FCP only occasionally)