Upgrading to from 3.2.4 to 3.3.3 [solved] - Joomla! Forum - community, help and support

i'm not techie, enthusiastic user of joomla. i've had through forum here can't find solution , don't know start.

1) i've taken complete site backup , installed somewhere else prove works before starting update.
2) running joomla 3.2.4 , have tried update 3.3.3 updates still shows 3.2.4.
3) have checked php version on centos 6.5 server. shows 5.3.3.
4) contacted server host explained although shows 5.3.3, up-to-date technique called 'backporting' being used , shouldn't compatibility issues joomla.

i'm guessing joomla update doesn't see 5.3.3 being latest version, , fails install because can't find 5.3.10 or later?

so, couple of questions:

a) how solve this, please? website working @ moment , i'm coming busy period in year customers reluctant have serious downtime although keen update.

b) can see in 'hosting settings' on server there dropdown box under 'php support' lists 5.3.3 5.4.23-custom. if changed setting 5.4.23-custom, mean using 5.4.23-custom? consequences might experience going 5.3.3 5.4.23-custom? settings need check / change / transfer if this? else need check? move change php versions?

all previous updates in joomla have gone brilliantly using 1 click update facility in joomla. first serious problem i've had.

could guide non-techie through solution, please.

thanks.

what following on minimum requirements joomla 3.3.3? http://www.joomla.org/technical-requirements.html

leo