Some basic troubleshooting steps to follow:
- First try clearing your cache and setting a fixed amount for cache management of 250MB (tools -> options -> advanced -> tab network; "clear now" "override automatic cache management")
After clearing, immediately exit the browser, and then restart it.
- If that doesn't help, try selecting "restart with add-ons disabled" in the "Help" menu. This will present you the "Safe Mode" startup dialog - try checking "reset toolbars and controls" and "reset all user preferences" and click "make changes and restart"
- If that doesn't work either, repeat the process but then also select "disable all add-ons; if that fixes it, the trouble is caused by one of your add-ons (that may not be compatible with Pale Moon 7.x), you'll have to enable them one by one and see which one is the culprit in that case.
- If even that doesn't work, something may be seriously wrong with your profile. Try starting Pale Moon's profile manager ("palemoon -profilemanager" from the command line), creating a new profile (and for sake of ease, tell it to show the profile manager every time) and see if that fixes your issue. If it does, please go to the following page for instructions on recovering important data from an old profile (for Firefox, but the same applies to Pale Moon)
http://support.mozilla.com/en-US/kb/Recovering important data from an old profile