[horde] elusive missing first character and blank page problem

[Per olof Ljungmark]

Jan Schneider wrote:
> Zitat von Per olof Ljungmark <peo at intersonic.se>:
> 
>> Hi,
>>
>>
>> At random, an action inside Horde, it could be a mailbox refresh, 
>> compose a message, open the address book or whatever, the user is 
>> presented with a blank page. So, it works most of the time but not 
>> every time and it is getting worse as well. Happens with both cache 
>> activated and not activated.
>>
>>
>> Warning: include_once(Horde/Cache/one.php) [function.include-once]: 
>> failed to open stream: No such file or directory in 
>> /usr/local/www/horde/lib/Horde/Cache.php on line 174
>>
>> Warning: include_once() [function.include]: Failed opening 
>> 'Horde/Cache/one.php' for inclusion
>>             ^^^^^
>> (include_path='/usr/local/www/horde/lib:/usr/local/share/pear:.') in 
>> /usr/local/www/horde/lib/Horde/Cache.php on line 174
>>
>> Fatal error: Call to undefined method PEAR_Error::get() in 
>> /usr/local/www/horde/lib/Horde/Perms/sql.php on line 270
>>
>> What part of Horde is calling "Horde/Cache/one.php"? It does look like 
>> this call is the one that misses the first character.
>>
>> PHP Fatal error:  Call to undefined method PEAR_Error::get() in 
>> /usr/local/www/horde/lib/Horde/Perms/sql.php on line 270
>>
> 
> Add a var_dump(debug_backtrace()); before that line Cache.php, to see 
> where this driver name is coming from.

This resulted in a lot of screen output when the error happened, but 
there are no references to "emcache" in this output, only to the correct 
"memcache".

php log now contains two more lines:

[14-Jul-2009 01:06:09] PHP Warning:  Cannot modify header information - 
headers already sent by (output started at 
/usr/local/www/horde/lib/Horde/Cache.php:174) in 
/usr/local/www/horde/services/javascript.php on line 34

[14-Jul-2009 01:06:09] PHP Warning:  Cannot modify header information - 
headers already sent by (output started at 
/usr/local/www/horde/lib/Horde/Cache.php:174) in 
/usr/local/www/horde/services/javascript.php on line 35