Yes and no. The parodies DONT district me if:
1. The central characters are very well established and it is clear that the parody is more of a brief cameo/funny bit rather than an on-going character.
Exceptions: The parodies can be an on-going occurence, if it follows the basis/theme of the comic. This usually works best in political comics such as Doonesbury.
2.Parodies are common in the particular strip and/or occur on a regular basis. In other words, the main jist of the strip is random fun-poking and parodies (i.e. Bizarro)
They DO distract me if:
1. Too much emphasis is placed on the "guest" character. The comic needs to clearly remain about, say, Muley and his chance encounter with Spock, and not Spock and what he can or can't teach Muley.
2. More than one parodied character appears in the comic (unless they are a set). OR if the character appears multiple times. That is when the gag gets old and the surprise and hilarity of seeing a familiar character runs out.
Exceptions: I believe this rule can be broken if it is done repetitively in a single strip/story. What I mean by this is that if I had say Bob Hope, and wanted to give him multiple cameos in a movie, I would strategically place him throughout the movie doing the same thing over and over again - interrupting during a dramatic scene, carrying something and getting in everyone's way, or steal a page from "Spies like Us" and have him play golf in everyone's way.
Goodness that was long! Sorry about that, lol! (english student + love for comics = over-analyzing)