Lower speaker volume after iOS4 update ?

I'm not crazy. I'm 20 and have great hearing. I'm used to using my iPhone as a "shower radio" and now after the 4.0 update the volume of my phone is decreased. I've checked the settings and the volume lock (or whatever it is called) is not set. Anyone having the same issue ?
I've searched, looked through some of the problem threads but have seen nothing..