I was happy to stick with Winamp 2.74 until .... it seemed to work alright on the first night, the timing MP3s were perfect and I tagged a file which worked fine on the empeg. Tried to tag another file a couple of nights later and got the lag problem.

I have now downloaded 5.08 lite and changed to the mpg123 plug-in. It works like a treat.

Thanks to all who came up with (and refined) the solution.