Its no big problem you can do 1 of 3 things you can go down to your local radio shack or whatever you have in your area and ask for a new mains lead in the UK these are called figure eight leads(because they look like the number 8 when looking head on) don't know what they are called in U.S A but its small enough to put in your pocket to compare.
2 You more than likely have one in your house all ready plugged into a tv or something you could try this to see if you have the same problem if not use this and use the Tascam one in the other appliance.
3 An easy fix is to wrap electrical tape round the outside of the plug so it fits in the PSU housing more snugly.