There are many conversion utilities, some of them free, such as this one that has worked great for me:
Just convert the flv file to a wmv or avi and import to PE7. No problem.
You also might want to look at Moyea's Adobe Premiere Plug-in.
I've been testing it in PrPro 2.0, and it works perfectly. I'm so happy with it, that I am going to pick up a second copy. Do not know if it works for PE7, but Moyea has other utilities around FLV, so there might well be something else.
With the Plug-in, PrPro 2.0 just Imports the FLV's, and PrPro works well with them.