I have just replaced the toners in my HP 8550 and now I have yellow splodges all over the pages when printing in colour (not in mono) - I am guessing that some yellow toner escaped, but I dont know where to start cleaning - any ideas please?
It sounds like it could be a bad "wiper blade" on the toner. This is somewhat common when reusing an old toner, i.e. if you bought the toner from a discount supplier like TonerPirate. To make sure, try doing a few cleaner pages and see if that works things out.