warnings from the IDE where there are no lines of code?

hello again, i seem to have various 'yellow warning bars' in my IDE highlighting a problem where there is actually no code?, or its highlighting a line in an area of commented out code?. whats going on. I have tried

• saving the file
• building the project(which indeed builds) to get rid of them. No change.
• closing the project completly and reopening it

why is this happening?. something is obviusly out os sync

any thoughts appreciated.