oh yeah... i have seen the same on some of mine...
btw... how long did it take your UG to acclimate to your tank???... mine seems to take forever... some of mine just keep uprooting and floating.... the other completely disappeared after i bought them... they maybe melted away....
i bought a bunch... but now there are only a very small amount left... is there any chance it will make it???
i noticed some have grown into some thread-like things without any leaves or roots.. however those things have the bladders... are those gonna develop roots and leaves later???
did you experience the same problem with your UG initially???...
also... since some of the UG are floating... can they still grow while floating?....
i planted my UG approximately around august 8th. it's established for the most part, i can see side runners and traps spreading through the substrate against the glass.
i think the reason why your UG floats is because you didn't dig deep enough. one thing to note is that the entire plant is quite versatile, leaves can produce traps, roots produce traps, roots come from leaves, so it doesn't really matter that you partially bury some of the leaves--they hold on better that way.
the thing about carnivorous plants is that they have a shock period where they are severely stressed going from one environment to another, during this time, they shed leaves and pull back a bit. however, once when they are established, they thrive.
another thing, although this isn't confirmed yet, but check your nitrate levels. utricularia, and carnivorous plants in general are adapted to nitrogen poor soils and conditions--high levels of nitrates could be responsible for your UG meltage.
UG can still grow when it is floating. it does not derive nutrients from the soil as dependently as other aquatic plants, but consumes small inverts (paramecium, baby amphipods).
as for your detatched root structures, i think you might be out of luck...the plant needs some sort of photosynthetic component in order to survive. leaves are probably most successful for speedy propagation.