Why am I suddenly getting this warning?

[twig/al]

My forum has been working fine, and tonight I got this warning:

Performance Warning

The cache directory is not writable - this will adversely affect the performance of your forum.
There have been no changes to anything in the control panel...

[Storman™]

Check your SMF cache folder and see whether there are actually any files in it or is it empty ? (report back). Also check what the CHMOD settings are for the folder.

If it's been working fine for ever and a problem suddenly occurs then it's usually something your host has changed without you knowing it.   

[twiggs]

 Storman, I think it is a host problem. Sorry for the delay and I don't have the problem fixed yet... If you can mark this solved and if I don't get it fixed with the host I will post again with more information... Again Thanks!!!