A quick fix in virtuemart

I am setting up a e-commerce portal using joomla and virtuemart. using joomla2.5x and virtuemart2 Having problem with my virtuemart where, during checkout, the page keep looping to ask me select payment method. If I activate more than 1 shipping options, then the cart will keep looping to ask me select shipping method when i want to check out. Need someone really good in php and virtuemart to help me resolve this. Those who have no experience in virtuemart and customizing knowledge please stay out. I need this urgent and expect to start the fix immediately. only big if you can start immediately. What is need is just a fix, not asking you to write a whole module or add any additional functions.