Naruto,
It has nothing to do with how radios are tuned. It has to do with the multiplayer call functions of the aircraft's coding. The T-38 had the same problem until it was brought to MILVIZ's attention, and it was fixed.
I also prefer to use TS, but I fly in an ATC session that sometimes has 50 pilots and 10 controllers all working on different FSX frequencies. This goes smoothly, until I load in the F-15, and then everyone else's comms crash.
Milviz knows what the issue is, I'm just not sure they know about it on the F-15.
Also, is there a support forum on the milviz page for the F-15, like there is for the T-38, or is there just the general forum?
CE