Problems with MTX in a 2004 6S

[UTMorpheus]

Okay let me start with the cars history. I just got the car (my first owned MTX) in November with 78K on it, now it has 80K on it. Ever since I got it shifting into first, third, and fifth felt...spongy. I wouldn't get the satisfying click that I would with second and fourth. About three weeks ago my shifter locked up and I was stuck in reverse. Took it to the dealer, they wanted $1000 after parts, labor, and tax to "replace a broken shift cable". I ordered the part ($330 + 70 overnight shipping) and decided to install it myself. After searching around on the forums I came across this thread: http://forum.mazda6club.com/index.php?showtopic=91212 and saw cerialkilla's post about some metal clip he made to fix the problem. I made that clip and welded the thing in place and it's worked ever since. So I returned the part to the dealer.

Now I'm having another problem, over the past week third gear has been not clicking into gear. I'd push on the shifter and it would return to center, I'd have to jam it forward and wiggle it to get it to engage in gear. As of last night it's not even doing that, and seems to have taken first and fifth with it. Second, forth, and reverse still shift accurately and normally and I'm able to drive it for the time being. My question is(for someone who has only basic knowledge of MTX but high technical/mechanical knowledge) any idea what is wrong and what would you recommend to fix it?