On some gas ranges, the broiler comes on with the bake selection during warm up. This allows the oven to preheat much quicker. More than likely, the control pad is functioning properly and your bake igniter is bad. Igniters become weak with age and eventually go bad. Since the bake feature is used more frequently, it typically goes bad more often. The following link provides you with some guidance on oven igniters:
http://www.fixya.com/support/r401858-replacing_oven_igniter_gas_range
Remember: just because an igniter glows, does not mean it is good. If they become weak, they will not draw the required current potential to open the gas safety valve.
If you determine the igniter to be bad, you can obtain a replacement at searspartsdirect.com. Just type in your model number and go to the "Gas Controls" heading and look for item number 14 (part number 74007498). If the igniter plug does not match the plug you have on your oven, the instructions will guide you to cut the wires and splice the ends together. There should be ceramic wire lugs that come with the igniter kit. CAUTION: Make sure you only use the ceramic (heat resistant) lugs that come with the kit. Splicing with regular wire lugs or electrical tape will melt due to the heat. Additionally, make sure you UNPLUG the appliance before replacing the igniter. Live voltage potentials are still present with the range shut off.
I hope you find this information helpful. Let me know if you require additional assistance.