Pentair Filter help!

I have a Pentair DE cartridge/grid filter (looks like R2D2 sorta).

Anyway, the guys that closed my pool left the band in the middle loose. I didn't know that till water started spouting everywhere from the middle. OK, I tighten it, and still the same. Then I see the top isn't on right, so I reseat it, but in the process, I have to loosen the band. The spring thing comes off the bolt completely, and I cannot get it back on. There is not enough thread for it, much less the washer too. It looks like it's pretty snug. Does one need to be a Neanderthal to get this thing back on? I /really/ need to get this thing running, I already shocked the pool, and it only ran maybe an hour before it leaked.

I got this filter last summer, btw, so this is the first time I opened with it.

I would say, start over from scratch.
Take the lid off. Re seat the gasket properly.lace the lid back on. check all the way around to make sure everything is seated and sealed properly. Put ring around and tighten. If everything above was done properly, it should fit.

Well, I caved and called the pool company. Took two of 'em w/me helping. We got it on, but they said it was the hardest one they've ever done. Damn thing's only 8 mos. old or so. A longer bolt would do the trick. All I know is, when I reopen (I don't close myself, I have no interest in blowing the lines, nor storing the tool it takes to do it properly) I will make darn sure that spring bolt doesn't come off. I'll shimmy it all into place. Either that or get a longer bolt between now and then.