I thought fondant or gumpaste on buttercream was a no no? Any thoughts on this issue?

I've never done it myself, but I've seen lots of photo descriptions on here that say "buttercream with fondant accents." So, it must be possible. I hope an expert chimes in with some real advice for you!

I've done it before with no problems. I just used a small amount of RI to attach the fondant/gumpaste decorations (I had made my decorations in advance, so they were dry...if your fondant was not dry, you might be able to get away with wetting the back with water and then placing it on the side.) With using RI, I just had to be careful not to use too much (but still use enough to hold it) or else the decoration would slide down before it had a chance to dry in place.

It always depends on many factors - the buttercream recipe, the fondant recipe, and your location /weather can play in it too.
When you use crusting buttercream, you are on safer side than with non-crusting. The same, if you put dried fondant pieces on buttercream - it is better than fresh/pliable fondant. Difference can make even how much buttercream there is.

The only way to be sure is to test your buttercream / fondant combo. Put some buttercream on a plate, let it crust / firm up the same you would your iced cake (or not...) and put some fondant accent on it. Store it as you would your cake, for the same time. See for yourself. Only than you can be sure - unless you find somebody who did it already in same conditions - be it as test or on a "real" cake.

Thank you to all those of you who responded!I will give it a shot. I am new to glogging and look forward to chatting and exchanging idea.