has anyone used those plastic tubing circular knitting needles sold on ebay to knit a sweater? i'm wondering if they are built sturdily enough to withstand the weight so as not to break when i push the stitches to the wire. they're made a little differently than the ones discussed on the make your own needle forums on crafster. here's a link to what the ebay needles look like. http://cgi.ebay.com/bamboo-knitting-needles-circular-32-US-5-15-U-nitt_W0QQitemZ120132883382QQihZ002QQcategoryZ71216QQrdZ1QQcmdZViewItem
it just looks like the plastic is shoved onto the needle.
they look like a fantastic price, but i don't want to get them if they'll instantly break on me.