hello, this is my first post on what appears to be a great forum, pleased i found the place!

my sister quite enjoys weeding, says she finds it kind of therapeutic ... i on the other hand hate it with a vengence! in my front garden there are 4 x borders surrounding a regtangle of grass, there's also a circle of earth in the middle. i've been in the place for just over a year and have recently planted up the borders with various evergreen shrubs as the previous owners seemingly gutted what had been a really nice garden, so i'm starting from scratch i suppose.

the thing is the garden is being plagued by this stuff:

http://img89.imageshack.us/img89/2804/garden1d.th.jpg

bit more of a close up:

http://img847.imageshack.us/img847/7500/garden2d.th.jpg

it looks innocent enough, as if it will just pull up quite easily and without resistance, no chance! it has a fine (thread like) root system that seems to run everywhere under the surface! i've tried turning the soil and pulling out as much as i can, turning the soil and using a weedkiller etc etc but give it 2-3 weeks and back it comes bold as ever

is there anything else i can try that might keep it at bay for longer or maybe eradicate it altogether ... or am i destined to have to weed every other weekend during warmer months for the rest of my puff?!?

oh and any ideas what it is?