It is possible something may have happened to the multi a/v port when you tried switching cables around but it is usually much sturdier than that. The tech support at Sony would be more apt to be able to figure out what is up there. If you do plan on going with the HDMI, however, you may be able to ignore it for the time being until your new cable arrives. Chances are they would say to have the system sent in (which is fine if under warranty but if over a year old would be very pricey) and would leave you PS3- less for a couple of weeks on average.
When you do get the cable, keep the component hooked up long enough to be able to switch the video output settings on the PS3 to the HDMI- you will be able to select what resolutions to use this way. My personal suggestion there is to leave things at 720p as the high end as hardly any games use 1080i (doesn't support fast frame rates) and the difference is hardly noticeable on movies.