Running really old version [1.23]...will I have any problems updating to current?

I haven't been here on mobileread for a while and haven't been updating Calibre either.

I am currently still on 1.23 and I see the current is 2.63.

Will I have any problems updating Calibre? That is quite a few jumps in releases. (94 if my math is right!)

I do plan to back my Calibre libraries up before I upgrade.

Any other advice?