messenger live build 8.5.1302.1018 takes 100% cpu on big contact l

At the moment a have a lot contacts added in my msn account.
When i connect messenger live with this account it will go 100%cpu, and
sometimes after a while i will slow down to normal, but most of the time if
will keep up to 100%cpu.

When i connect the messenger to some other test-msn-account with an empty
contactlist, all goes fine, and no 100%cpu.
Someone knows how to fix this ? withouth cleaning down the whole contactlist.

Thanks for the help!