whats going on? torque converter?

[h2003]

my 03 h2 drives and shifts fine until i get to 40mph cruising around town and it goes into overdrive. when it does the rpms bounce up and down about 300 rpm if i stay at a steady speed. this goes away after 50 mph but its annoying!!! had it at dealer he said he could get it to go away by increasing pump pressure during diagnostic but they are steering me toward a rebuild. i dont know what to do. should i just live with it? thans.

[Guesst]

just had my torque converter replaced a month ago... when it went bad the hummer would shift through 2nd and third gear but in third it felt like it was slipping, it wouldnt accelerate and it would just stay in high rpm... thought maybe it was the transmission but ended up just being the converter... dont know if you have that same problem or not... my tran light in the dash went on too...