error message "maximum number of allowed clients (100) are already connected"

Hello,
i am new here.

Since yesterday, when ftp export the error message: 
---
[manage_customizeFtp]: Traceback (most recent call last): 
File "C:\Programme\WebSiteZope\lib\python\Products\zms\_ftpmanager.py"
, line 180, in manage_customizeFtp ftp.login
(self.attr_provider_ftp_userid,self.attr_provider_ftp_password) 
File "C:\Programme\WebSiteZope\bin\lib\ftplib.py", line 318, in login 
if resp[0] == '3': resp = self.sendcmd('PASS ' + passwd) 
File "C:\Programme\WebSiteZope\bin\lib\ftplib.py", line 229, in 
sendcmd return self.getresp() 
File "C:\Programme\WebSiteZope\bin\lib\ftplib.py", line 202, in 
getresp raise error_perm, resp error_perm: 530 Sorry, the maximum 
number of allowed clients (100) are already connected. (11.02.2008 
09:13:52 
---
I actually have changed nothing on the configuration.

Thanks for the help.

Best Regards

Andreas

System:
WinXP SP2

ZMS: 2.1.2.7 (Build #117b)
ZOPE: (Zope 2.6.1 (binary release, python 2.1, win32-x86), python 
2.1.3, win32)
PYTHON: 2.1.3 (#35, Apr 8 2002, 17:47:50) [MSC 32 bit (Intel)]
System Platform: win32
System Time: 2008/02/11 09:20:28.150 GMT+1
Running For: 1 hour 27 min 34 sec
ZODB Location: C:\Programme\WebSiteZope\var\Data.fs
Database Size: 428.6M