Why is my forum so slow?

[Sonia]

Trouble

1) I can't open forum.  
2) When I open the forum, forum works very slowly.

This is not happens  all day, but only sometimes.  For example  1/2 hour or 15 minutes forum is  frozen

http://arsepo-forum.1055779.n5.nabble.com/

PS:  Right now:  Forum does not load

[Sonia]

Here is same problem

http://se-sheet-sims-3.22190.n6.nabble.com/

Embed http://se-sheetsims3.blogspot.cz/

[Micke]

I have the same problem in my forum since yesterday. The forum is useless and I get complains from my members.

Please do something.

Best regards
Micke

[Pedro]

It might have been a glitch or an overload on our servers. Let me know if it happens again.