The problem is I'm getting the "Advertise Here" ad displayed on occasion when WP125 has a set of 7 ads to choose from.
Please help me a bit to understand the situation :
1. Now you have configured it to 4 and you can see the 4 Ads like I am.
2. But, if you configure it to show 7 then that Grey default sample Ad shows up in random manner.
If the second one is the fact, there might be a bug in the plugin or some other PHP loop is preventing somehow.
(1) If you do not need to rotate the Ads, but want to show the Ads constantly with same codes, then creating a simple div and css can practically give you the freedom from WP125 plugin itself.
WP125 does have some peculiar bugs from my own experience. (In past one one month I have not seen the plugin developer to respond to solve the user's problems...)
(2) If you need to rotate the Ads, then create a div with inline css and deliver through Ad injection plugin. It has widgets too.
(3) The needed HTML and CSS codes are basically easy. But if you are not used with HTML + CSS, simply you can search on Google or ask us.