I wonder if the wrong fuse was in there in the first place?
Either way, I'd take my VOM and measure the current going thru the fuse. I'd be curious. If it's just a *little* out of spec, it could be weary diodes or transistors maybe drawing a bit more than originally designed for. Maybe add some heat sink if so.
If you decide to run it as is, maybe put in a slow-blow fuse 10% higher than what it's actually drawing at the moment. That way, if a transistor or diode shorts out, or if something else starts pulling even more current, then the fuse will save you from having to replace too many parts.
Keep us posted!
Peace,
Bud