thoughts on kreepy crawly type vac- leisure vac/zap vac 2

i recently got a zap vac 2..exactly the same as the leisure vac and very close in design and function to some of the creepy crawly models, anyway. i got it setup and put the weight about 3 ft back to start as recommended on a guide i saw online. i found the vacuum was continually migrating to the edges and rarely going center. i put the weight further a bit further back and bit by bit way further back and it still went center. tried changing pressure, closing off main return partially, completely. (getting a great amount of suction as long as main valve is partially or completely closed) tried adjusting the regulator..still kept cleaning the sidewalls pretty much exclusively.

so, yesterday, i decide to play with it some more and work the weight from 3 ft going IN rather than back given info i've read says closer you go in, the less it should climb the walls..well, got to the point where the weight was right at the top of the vac and it was coming off the edge but in every "pass" on the pool, was always going to the edge for awhile. i'm thinking, ok..what the heck..i've done everything i described above, changed the hose length (shorter, longer) and it's still acting like a "wall crawler" 90% of the time.

now, here is what is weird. in my last ditch effort inspired by trying everything else i could think of, as i stood by the pool having a smoke (and needed a drink by this time:)) i took off the float for the heck of it..adjusted nothing else and let it go..when it hits the wall, it stays there for a few seconds..and starts another pass across the pool..and keeps doing it!

darned if i can figure out why removing the float worked..but it did!