The following Python implementasion demonstrates how to create a GUI application for srcaping jokes from Qiusihbaike using Tkinter for the interface.

#!/usr/bin/python
#coding:utf-8

import urllib2
import re
import sys
import datetime
from Tkinter import *
from HTMLParser import HTMLParser

class JokeScraper:
    def __init__(self):
        self.current_page = 1
        self.headers = {'User-Agent': 'Mozilla/5.0'}
        self.joke_cache = []
        self.page_cache = []
        self.output_file = 'jokes.txt'
        self.file_handle = open(self.output_file, 'wb')

    def fetch_page(self, page_num):
        try:
            url = "http://www.qiushibaike.com/text/page/" + str(page_num)
            request = urllib2.Request(url, headers=self.headers)
            response = urllib2.urlopen(request)
            return HTMLParser().unescape(response.read().decode('utf-8'))
        except Exception as e:
            print "Connection error:", str(e)
            return None

    def parse_jokes(self, html, page_num):
        jokes = []
        author_pattern = re.compile(u'<h2>(.*?)</h2>', re.S)
        content_pattern = re.compile(u'<span>(.*?)</span>', re.S)
        
        authors = re.findall(author_pattern, html)
        contents = re.findall(content_pattern, html)
        
        for i in range(len(authors)):
            text = re.sub(re.compile("<br/>"), "\n", contents[i])
            jokes.append([str(i+1), authors[i].strip(), text, page_num])
            self.page_cache.append([str(i+1), authors[i].strip(), text, page_num])
        
        return jokes

    def load_more_jokes(self, html, page_num):
        if len(self.page_cache) < 20:
            self.parse_jokes(html, page_num)

    def get_next_joke(self):
        if len(self.page_cache) > 1:
            joke = self.page_cache.pop(0)
            return joke
        else:
            html = self.fetch_page(self.current_page)
            self.load_more_jokes(html, self.current_page)
            self.current_page += 1
            if len(self.page_cache) > 1:
                return self.page_cache.pop(0)

    def display_joke(self):
        joke = self.get_next_joke()
        timestamp = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S ')
        output = "Page %s Joke %s\nAuthor: %s\n%s\n\nPosted: %s\n" % \
                (joke[3], joke[0], joke[1], joke[2], timestamp)
        self.file_handle.write(output)
        return output

def clear_display():
    display_box.delete(1.0, END)

def show_joke():
    display_box.delete(1.0, END)
    display_box.insert(1.0, scraper.display_joke())

if __name__ == '__main__':
    scraper = JokeScraper()
    
    root = Tk()
    root.title('Qiushibaike Joke Viewer')
    
    title_label = Label(root, text='Qiushibaike Jokes', justify=CENTER)
    title_label.grid()
    
    display_box = Text(root)
    display_box.grid(row=1, column=0, columnspan=2)
    
    next_btn = Button(root, text='Next Joke', command=show_joke)
    next_btn.grid(row=2, column=0)
    
    clear_btn = Button(root, text='Clear', command=clear_display)
    clear_btn.grid(row=2, column=1)
    
    root.mainloop()

This implementation includes:

1. A dedicated class for scraping and managing jokes
2. Proper HTML parsing and error handling
3. Simple GUI with Next and Clear buttons
4. Persistent storage of scraped jokes
5. Automatic loading of additional pages when needed