I have a pretty strange vibration issue in our 2005 Accord Euro CL9.
The car has travelled approx 165000kms.

The vibration is only evident at around 2500rpm in 2nd gear (around 38km/hr on the speedo). This vibration is not felt through the brake pedal (so not warped rotors or steering). Generally only felt when accelerating through 2500rpm (and is evident only in that narrow band). It is not very severe, more moderate in nature. Have now had this for about 2 years.

Can't really feel this vibration in any other gear, at the same 2500rpm (i.e no vibration in 1st, 3rd of 4th gear at the 2500rpm mark) - so its only in 2nd.

Initially thought it was the infamous drivehshaft issue, however - have replaced driveshafts with good quality items twice now (both drivers and passenger side), and the vibration still remains as described above.

After changing the driveshafts, I wondered whether it was the ageing original clutch. However I changed the clutch recently with OEM components. Clutch is now great, but vibration remains. I have also recently changed all brake rotors and brake pads,

Wondering if this could be one of the engine mounts. Still have original engine mounts.
Apart from the above vibration issue, the car is in good nick, and drives well.

Any ideas on what could be causing the above ?

Thanks.