Colour problem with CS5 & Lightroom 3

[siman23]

For some unknown reason my photos are not looking right in CS5 & LR3, they were fine last time I used them and I have not changed any settings, they look fine in windows viewer, nero etc but in CS5 & LR3 they look too saturated or the blacks are too black, some people would hardly notice it but I do, something is definately not right but I can't figure it out.

Any help appreciated!

 

[Peter_Hartland]

Have you changed the profile settings in preferences firstly, then check in View if you have a strange custom proof. They are the usual suspects

 

[siman23]

Thanks for reply, I checked all that even though I had not changed anything.
Have sorted it, for some unknown reason the colour profile of my monitor had changed! Have no idea how.