Somewhat related issue...

On the currently active public Continental.com site.

Went to select seats for a purchased reservation. No problem getting exit rows on the 737-800 segments.

Then try to select 14F on a 735. It shows available and lets me click on it, but when the screen goes back to the reservation the assignment won't stick. The others are fine.

Called co.com support and after some waiting and reading off the exit row responsibilitie the agent was able to get it assigned.

Strange.