If you are having problems deleting watch list items from your Summary page, try using the checkbox in front of the item and the "delete" button at the top of the list rather than the "delete item" link that appears when you hover your cursor over the item.
There does seem to be a problem with those "delete item" links -- I was not able to get them to work in any browser since early February. Not sure when that problem started; I had not noticed it until recently.
Take care not to accidentally delete all of your items, though. If you select the checkbox at the top of the list, that will select all the items on the page.
If you are actually having problems deleting items from the Watch List page itself and you are using Internet Explorer, try another browser instead. If you are still having issues, try deleting items from the Summary page as described above.
It is also possible to delete Watch List items directly from the item page, but due to another current bug you will have to use the "add to watchlist" button first to be able to see the "remove" link at the top of the page in the blue band.
If you still have difficulties or you find a particular item is "stuck", try this "All Lists" link -- find the item on this list of all of your watched items and delete it there:
https://my.ebay.com/ws/eBayISAPI.dll?MyEbayBeta&SortOrder=ASCEND&GotoPage=1&MyeBayListIndex.Filter=A...
For some reason this last method works when others seem to fail.
