It used to happen to me too. Secret is to push the air out valve in as hard as you can. I use my teeth to push in the last little bit. Also, on the air in valve you need to push the velcro down a little bit and squash the end towards the ridge. Then push down again. Leave the velcro a bit loose. I also close off all of the struts just in case, although I haven't had any problem since I started following the above proceedure.
if they arent pushed in properly then they arent going to work check the velcro too it might have worn out. and remember the fuels dont have to be pumped up as hard as alot of the other brands. use your gauge about 7 psi is recomended. but yeah push that air out valve right in.
That is also a good method for getting temperamental ballpoint pens to work again (without the hose nozzle though). If ever you only have one ballpoint pen, it is temperamental, you need to write something down, and you have plenty of access to hot and cold water... A perplexing situation I found myself in one day...
The Green Baron Terror of the skies and vanquisher of poor spelling everywhere (now I'm going to look silly if I make a spelling mistake)