Yes, you are missing something. What you put in a memory location is not what the R30 uses for a tuning step when you are in VFO mode. It defaults to 8.333 for VHF air.
In VFO mode, set some frequency such as 119.1, then push the 9 (TS) key and rotate the dial to 25Mhz and push the MENU/ENTER key. You have to do that for both the A side and the B side since they are independent of each other.
You have to do the same thing on both the A and B side for UHF air also, however it defaults to 12.5 for tuning step.
Also --- I have not found any way to permanently edit the band plan in the R30 to change the default tuning steps.
One more thing --- depending on which software package you use to update what is stored in memory in the R30, you will have to go back and change the tuning steps for the VHF and UHF bands after you write from you computer to the R30. For example, I use the CS-R30 package from ICOM, and it resets the tuning step for all the bands when I write to the R30.