Do you regularly format your memory cards in the camera? that's the first thing you might try.
The "red error light on" statement also suggests to me that the memory card is not writing correctly for some reason. There is no such thing as a "red error light". As David wrote, the red LED on the back of the camera indicates the memory card is in use. It could be an issue with the camera, but much more likely it's with the card itself.
You state the card is "30 MPS", so I am assuming you are talking about a Class 10 SDHC card. That was a "fast card" in 2008. Today it's sort of on the slow side. Sandisk has a half dozen or more cards that offer faster 45 MB/sec, 60 MB/sec or 95 MB/sec.
So I suspect you are simply bumping up against the buffer, since you say this occurs when shooting continuously. In other words, after shooting a series of 20+ MB images, it takes a while for the camera's buffer to move all the images onto the memory card, and the camera halts while doing that. If you are shooting RAW, the files might be 30+ MB. If you are shooting RAW + Large JPEG, each image might be generating both a 30+ MB CR2 file and around a 15 or 20 MB JPG file. That's a lot of data to move quickly.
You might try using a Compact Flash card instead. I don't know if they can be compared directly, but the slowest CF cards typically being sold today are around 45 or 60 MB/sec. Faster ones are available up to 120 or even 160 MB/sec.
So, ultimately I suspect you're just seeing an issue due to a slower card, not a real problem with either that or the camera. Get better, faster memory and you'll likely solve the problem (but still might be able to fill the buffer and see the camera pause to clear it, if you rapidly take an extended series of RAWs or RAW+JPEGs).
If you do try a CF card, don't leave the slower SDHC card in the slot... the camera might slow itself down to match the slowest memory card in the multiple slots.