Route Me: Caching Tiles limit?

Question

I am using the route me frame work for my map application. I badly want to cache more tiles than its caching by default. So i changed the routeme.plist like this:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<array>
    <dict>
        <key>capacity</key>
        <integer>16</integer>
        <key>type</key>
        <string>db-cache</string>
    </dict>
    <dict>
        <key>capacity</key>
        <integer>100000</integer>
        <key>minimalPurge</key>
        <integer>5000</integer>
        <key>strategy</key>
        <string>LRU</string>
        <key>type</key>
        <string>memory-cache</string>
        <key>useCachesDirectory</key>
        <true/>
    </dict>
</array>
</plist>

But it doesn't matter which values i change, the app always reloads tiles which i have already seen before. Is there a limit for caching?