Mine stripped, but I decided to solve the problem by getting a package of screws and nuts from the hardware store. Unfortunately I didn't make a note of what size I bought. I took one of the screws with me and bought 1" long screws with nuts.
I drilled the original screw-holes through to the bottom of the base using a 1/8" bit, then turned the base over and used a 1/2" drill bit (note: do NOT use a "spade" bit, use a normal "twist" style bit) to drill out some shallow holes on the bottom, just deep enough to hold the nut. Then I just put the longer 1" screws through and attached the nuts.
I preferred this solution because I can now loosen, adjust, and tighten the flexi stands if I want to.