2004 Ls430 Transmission Problem

[Illinois]

I traded a 2002 LS430 for a 2004 version in December. I have an annoying problem when accelerating from a reduced speed like going through an unmarked intersection, entering main highway from driveway, etc. When pressing the accelerator to increase speed, there is a short period of what I call "loose motion" as if the transmission is not totally engaged for a second or two. The tachometer even briefly bumps up reflecting an attempt to get totally engaged. Result is a slight jerk......on a $65K automobile. Bizarre! ....and quite annoying. Did not have the problem on the 2002.

Took it to the service dept......technician agreed there is a problem....BUT NO FIX at this point............ any suggestions? any similar problems? I have also contacted Lexus corporate to advise them of annoyance.