Magento

Hi folks

I have just upgrade of my site to upgrade to version Mag 1.3 and got following error. Please suggest any possible solution without reinstall a whole copy of magento. I can not access front and backend… ;-(

Notice: Array to string conversion in /home2/primecar/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php on line 352
Trace:
#0 [internal function]: mageCoreErrorHandler(8, ‘Array to string...’, ‘/home2/primecar...’, 352, Array)
#1 /home2/primecar/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(352): explode(’_’, ‘Array’)
#2 /home2/primecar/public_html/app/code/community/LKC/ModularRouters/Router/Standard.php(105): Mage_Core_Controller_Varien_Router_Standard->getControllerFileName(Array, ‘index’)
#3 /home2/primecar/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(158): LKC_ModularRouters_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#4 /home2/primecar/public_html/app/Mage.php(457): Mage_Core_Controller_Varien_Front->dispatch()
#5 /home2/primecar/public_html/index.php(52): Mage::run()
#6 {main}

many thanks in advance