[TYPO3-english] sql error at logout - felogin / kb_md5fepw

[Thomas Meixner]

Hello,

I'm plagued with an intermittent error on my TYPO3 4.2.6 portal site. If 
I disconnect a fe user account sometimes it throws an error message. It 
happens about 1 in 20 times so it's difficult to debug. If you know 
what's happening could you please give me a pointer, I'm at a loss here. 
I have pasted the error output below as well as a screenshot here:
http://www.avecstyle.ca/logouterror.png



Thanks in advance,
Thomas Meixner


-----------------------------------------------------------------------
caller  	t3lib_DB::exec_INSERTquery
ERROR 	Duplicate entry '32e6b7e882d6d61d2fd28de39533623c' for key 1
lastBuiltQuery 	INSERT INTO tx_kbmd5fepw_challenge
(
challenge,
tstamp
) VALUES (
'32e6b7e882d6d61d2fd28de39533623c',
'1237387901'
)
debug_backtrace 	require#76 // tslib_fe->INTincScript#461 // 
tslib_fe->INTincScript_process#3012 // tslib_cObj->USER#3086 // 
tslib_cObj->callUserFunction#724 // call_user_func_array#5866 // 
tx_felogin_pi1->main# // tx_felogin_pi1->showLogin#114 // 
t3lib_div::callUserFunction#285 // call_user_func_array#4491 // 
tx_kbmd5fepw_newloginbox->loginFormOnSubmit# // 
t3lib_DB->exec_INSERTquery#78 // t3lib_DB->debug#181