it sound like your windows need adjusting so the gasket is doing its job,or the gasket needs replacing,with tilt and turn windows you have to know what your doing or it could get worse so your best off ringing a few double glazing repair companys in your area and get a few prices,feel free to contact me through my website if you want to try and do it youself
shaun www.sdwupvcrepair.co.uk
February 2008