My K-5 takes more than 99 shots in a time lapse sequence. A 99 shot limitation on time lapse sequences is pretty useless for making a video. Most video needs to be played back at 24 frames per second, so 99 seconds results in a 4 second video.
Here's one from last week with a K-5. One shot every 3 seconds for 30 minutes, which is 600 shots. The video is 20 seconds long, at 30 frames per second. This is about 8 Mbytes, so it will take some time to load
Mt Hood Sunrise
Can't imagine why your K-5 doesn't do this - maybe it has K-7 firmware instead? Also you might check you're not trying something like 10 sec exposures with a 1 second interval - although I think this ends up with 10 second exposures, with one second between exposures.