The guy who sold it to me said make sure you use the 1.55v silver oxide SR-44 batteries.
Is there any particular reason for that? I've heard that before but bought the alkaline anyway...
I think Francois has given reasons why already. I can only assume the guy who sold me my XA must have had a bad experience with the LR44 batteries.
Doing a bit of reading on net, John Hermanson on another forum (RFF) says "When the XA was new and we couldn't make them fast enough, Olympus factory said alkaline (LR44 & A76) are wrong for the XA. We saw the affects in the Olympus service department when XAs came in with the wrong batteries. They can cause meter needle position errors and sometimes shutter lock. They are also wrong for the OM-2/2N"
I know that cameras like my Pentax Spotmatic have an built-in voltage regulator so they can use 1.5V LR44 batteries in place of the old 1.35V mercury batteries, without any problem. Maybe someone could confirm if the XA has a voltage regulator too or not and hence the preference for SR-44 batteries much more constant voltage over their lifespan.
The other advantage of SR-44's is the ability to deliver a greater peak current then the LR44's for both of the XA meters and shutter.
LR44's do work, but note that not all LR44's are equal, you really do get what you pay for, if you are going to use them make sure they are fresh I guess, especially if you are shooting something like a wedding but the same would apply to SR-44's too.