Tricky to know for sure as don't know what you mean by "blips"
But if the files are playing back ok on the computer then it's probably safe to assume that the skips are not in the files but caused by the player having problems playing them.
Check in the manual what bit rates the MP3 player supports and make sure your files are not encoded in a higher bit rate than the player supports, I'd pay particular attention to if the player supports variable bit rate and if it doesn't then make sure your files have not been encoded in VBR.