Sitecore ERROR rebuilding “Quick Search Index” aft

I attempted to install WebForms for Marketers 2.4 on Sitecore 7.2 Initial Release. The install process would just hang, and never finish. I ultimately restored the databases from a backup, and restored the file structure. However, we started seeing hundreds (1300+ in the last 12 hrs) of these errors in the logs:

ManagedPoolThread #11 23:59:31 ERROR Could not update index entry. Action: 'Saved', Item: '{656E306F-8837-42E6-8334-38E44D39B736}'
Exception: System.Threading.LockRecursionException
Message: Recursive read lock acquisitions not allowed in this mode.
Source: System.Core
   at System.Threading.ReaderWriterLockSlim.TryEnterReadLockCore(TimeoutTracker timeout)
   at System.Threading.ReaderWriterLockSlim.TryEnterReadLock(TimeoutTracker timeout)
   at System.Threading.ReaderWriterLockSlim.TryEnterReadLock(Int32 millisecondsTimeout)
   at Sitecore.Search.IndexDeleteContext..ctor(ILuceneIndex index)
   at Sitecore.Search.Crawlers.DatabaseCrawler.DeleteItem(Item item)
   at Sitecore.Search.Crawlers.DatabaseCrawler.UpdateItem(Item item)
   at System.EventHandler.Invoke(Object sender, EventArgs e)
   at Sitecore.Data.Managers.IndexingProvider.UpdateItem(HistoryEntry entry, Database database)
   at Sitecore.Data.Managers.IndexingProvider.UpdateIndex(HistoryEntry entry, Database database)

FYI... all of these errors reference GUIDs for these 7 items:

/sitecore/system/Tasks/Schedules/CleanOutItemLocksTask
/sitecore/system/Tasks/Schedules/Email Reports schedule
/sitecore/system/Tasks/Schedules/ldapScheduleTask
/sitecore/system/Tasks/Schedules/SyncEverythingTask
/sitecore/system/Tasks/Schedules/UpdateNewsEventsCategories
/sitecore/system/Tasks/Schedules/SyncHotItems
/sitecore/system/Tasks/Schedules/UpdateTbisTags

My first fix was to rebuild the indexes. Rebuilding the Core, Master, and Web database indexes was successful. Rebuilding the "Quick Search Index" produces this error:

Job started: RebuildSearchIndex|System.Threading.LockRecursionException: 
Recursive read lock acquisitions not allowed in this mode.
   at System.Threading.ReaderWriterLockSlim.TryEnterReadLockCore(TimeoutTracker timeout)
   at System.Threading.ReaderWriterLockSlim.TryEnterReadLock(TimeoutTracker timeout)
   at System.Threading.ReaderWriterLockSlim.TryEnterReadLock(Int32 millisecondsTimeout)
   at Sitecore.Search.IndexUpdateContext..ctor(ILuceneIndex index)
   at Sitecore.Search.Index.Rebuild()
   at Sitecore.Shell.Applications.Search.RebuildSearchIndex.RebuildSearchIndexForm.Builder.Build()|Job ended: RebuildSearchIndex (units processed: )

I'm still googling for possible solutions, but I'd be grateful for any advice you might have on this.

Thanks jRobbins... I didn't think of this until now... I restarted the Sitecore application via Web.config modification (i.e., changing anything in the Web.config and saving it restarts the app), and that seems to have fixed the issue. Maybe this will be helpful to someone else in the future :]