IP address and secure sites

[#1]

Not sure where to post this query but ...
Yesterday,after the RBS/Natwest "meltdown", I still couldn't even get to the Bank's log in page, I got an SSL type error whichever browser I used ...until I was advised to disconnect/reconnect to force a new IP addy. Immediately the website starting working OK.  Why would this work???

[#2]

If it did start working purely because of the new IP that could suggest some kind of block was in place for the previous one.

[#3]

Yes,thats what I thought when I couldn't get in...but why???
Normally, I can get to the log in page from any computer so it isn't IP address specific - I know that some banks are tying access down to a specific PC by use of some sort of identifier cookie downloaded onto the selected PC (Tesco Bank for instance) but I couldn't even get to the log in page -just wouldn't establish a secure session. Oh well -another one of life's many mysteries
EDIT -The bank couldn't help me!! -it was a suggested fix from a member of another (financial) forum

[#4]

Quote

Oh well -another one of life's many mysteries

Or you could ask your bank if you know what the IP was