yet another fatal php error

hi there. Its me again. I get this error every now and then.

[DATE TIME] PHP Fatal error: Call to a member function getContentString() on a non-object in /templates/mobile_iphone/error.php on line 16

Joomla 1.5.25

Any help on that one?

How did you get it? In MJ it's impossible to switch to mobile template without initializing MobileJoomla class.

I have no idea. I get it in the error_log

Do you know http request (what url was requested) corresponding to this [DATE TIME]?

not really. all i know is that it happens every 9th and 12th hour (am and pm) appeared 4 times so far
i have jomsocial installed and i also have enabled component on home page (jomsocial is the homepage)

maybe i can try to find it in access logs