Tempo slower than playback when exporting in Sibelius

Hey, I'm trying to export this song and make it and MP3 so I can post it here, but everytime I click export it slows the tempo down a very large amount. I have the tempo set at 142, but when I export it slows it down to about 85 to 100 as the tempo. Does anyone have any idea what's wrong?

Maybe your computer is not fast enough with processing the data.

I have noticed that recording requires a lot more computing power than just playing back.

Maybe your computer is not fast enough with processing the data.

I have noticed that recording requires a lot more computing power than just playing back.

My computer has 1 GB of RAM and a 1.8GHz processor. Shouldn't that be enough to just use the Sibelius Essentials sounds? Plus the first one I wrote which was a full orchestra (this one was only piano) got exported without any problems.

Maybe other programs or processes you have running (even without you knowing) use up a lot of processing power. Have you had the computer running for some time? Does restarting, then starting sibelius and exporting help?

Maybe other programs or processes you have running (even without you knowing) use up a lot of processing power. Have you had the computer running for some time? Does restarting, then starting sibelius and exporting help?

I'm gonna try that.