If you use Sync, best is to disconnect Sync temporarily during troubleshooting.

You can check for problems with the places.sqlite and favicons.sqlite files in the Firefox profile folder.

• use the "Places Database" -> "Verify Integrity" button in "Help -> More Troubleshooting Information" (about:support)

If errors are reported with "Verify Integrity", close and restart Firefox or reboot the computer and retry.

If "Verify Integrity" cannot repair places.sqlite, rename/remove all places.sqlite and favicons.sqlite files in the Firefox profile folder with Firefox closed. Firefox will rebuild places.sqlite and restore the bookmarks from the most recent JSON backup in the bookmarkbackups folder.

• keep a backup copy of places.sqlite in case a new places.sqlite database has to be created
• you lose the history when a new places.sqlite is created

You may have to restore an older bookmarks backup in the bookmarkbackups folder via the Bookmarks Manager (Library).

• Bookmarks -> Manage Bookmarks -> Import & Backup -> Restore
• https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them

See also:

• https://support.mozilla.org/en-US/kb/fix-bookmarks-and-history-will-not-be-functional
• https://support.mozilla.org/en-US/kb/cant-add-change-or-save-bookmarks

You can use the button in "Help -> More Troubleshooting Information" (about:support) to go to the current Firefox profile folder or use the about:profiles page (Root directory).

• Help -> More Troubleshooting Information -> Profile Folder/Directory:
  Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

Many thanks for trying to help me, but the problem still stands, most of my bookmarks now take me to recent ebay pages, ive also tried yet another reinstall of firefox should i delete my ebay account from my pc, nearly all these bookmarks were generated from firefox, only a few were imported , regards patrick

Deleted as this was essentially a duplicate post.

Patrick, have you checked the URLs of the bookmarks?

For example, if you have a bookmark for Google but it takes you to an eBay site, is the bookmark itself pointing to Google or EBay?

You can check a bookmark's URL by right-clicking it and selecting Edit Bookmark…

I am just curious as to whether you are being redirected to EBay, or whether the bookmark itself is pointing to EBay etc.