I was going through Mt. Silver looking for items, when I ran into several battles with my Max Repels. Do repels not work at Mt. Silver or is my game broken? Help!
What level is the Pokemon in your first slot? Repels only stop encounters for Pokemon that are a lower level than the first Pokemon in your party.
If your Pokemon are lower than Lv. 40 and you are using repels, Pokemon will appear
Here is the link to Mt. Silver
scroll down to where it says Gen IV and look at the levels of the Pokemon to see if they are a higher level than yours.