Originally posted by Astronamy I have the Pentax K-m and looking at getting an IR remote
Have you checked the K-m's setup menu options for bulb? I believe most, if not all Pentax dSLR's with IR offer a choice of 'press & hold' OR 'press twice'. It's your choice.
For long shutter times, 'press twice' works fine and has a LOT less battery wear than 'press & hold' - - which is what a button locking type IR release is doing.
By the way, I just paid US$1.65 including shipping for a generic Pentax IR release.