unable to access gmail account from phone but can from pc

Hi, hope you can help.  I appear to have lost access to my gmail account from my phone.  I can access the account form a PC but the account no longer appears in the 'acconuts and snyc' list - It is blank.  When i try to sign in (setup new account - create - signin) it says it is trying to connect to the google servers then times out with the following message; 'can't establish a reliable data connection to the server, this could be a temporary problem or your phone may not be provisioned for data services.  If it continues, call customer care.'

Its been like this for about 2 weeks, so not temporary, and i have all relevant wifi / 3g connection ability.

Before spending a long time on the end of a phone with 'customer care' i was hoping someone else might of had a simliar issue, or atleast some advise to try.

I wait in anticipation.

Thank you, a 'new' user.  nsj355

Thank you for your reply.  Indeed 'enable IMAP' was deselected, so tried again after selecting 'enable IMAP', but it still times out when trying to connect to the google servers.
aargh!......

IronSingh,
I have neither updated via kies or attempted to any kind of reset.  If i was to do a soft reset, how would i do it and what will i lose from my phone?

had the same problem, tried to solve it as u advise and it works. of course, loosing all data, settings and apps installed.