I take it by "Adblock" you mean Adblock Plus.

1. Open the Blockable Items pane, either by clicking the toolbar icon and choosing the respective menu option, or by pressing Ctrl+Shift+V.
2. Visit a site where something is blocked.
3. Review the list of blocked and hidden items in the Blockable Items pane. Make note of the Filter Source column; items from a filter category like "My Blocking Rules" are filters that you've added yourself.
4. Once you've identified a custom filter you want to get rid of, right-click the blocked or hidden item and choose Edit Filter in Effect. This will open the Adblock Plus preferences window and highlight the filter in question.
5. Right-click the problematic filter and choose Delete to get rid of it, or just clear the checkbox next to it to merely disable it.

Before your answer came, I tried Dial-a-Grandson. Got it fixed. Thanks for your response, though!!