Trying to use 2 different bluetooth dongles and 2 bluetooth headsets, all from different manufacturers. The first bluetooth adapter works with both of the headsets (I can get and send sounds to it). The second bluetooth adapter only works with one of the headsets, giving some LMP response timeout for the second headset.

Hope there is some simple way to resolve this

have you paired about devices with both dongles?

Yes, I have tried the following:
adapter 1 > headset 1 (works)
adapter 1 > headset 2 (works)
adapter 2 > headset 1 (works)
adapter 2 > headset 2 (does not work)
adapter 3 > headset 1 (works)
adapter 3 > headset 2 (does not work)
all with pairing etc.

Today I tried the third adapter (a slight variation of adapter 2) on a fresh install on another box. The second (and third) adapters do work for other functions such as virtual serial ports and obex transfers

edit: I might come to the conclusion that the second (and third) adapters didn't support SCO/AV, but they do however work on the first headset