problem with radio after remote start

A customer came to my shop and had a compustar starter installed in a 96 malibu. The customer has since come back with the complaint that some of the buttons on the radio no longer light up.  For example, pre sets # 2 and 5 light up, but the others do not. The rest of the dashlights work. The fuses are good, parklights work. Only some of the buttons on the deck no longer light up.

Am I wrong in coming to the conclusion that this is an internal problem with the radio and happened coincidently around the same time the starter was installed? She is of course looking to me to do something. Everything I understand dictates that this would be the above stated situation, but I have seen weird things happen before and wanted to get some other input.

Thanks

does this only happen on RS? if you unplug the alarm brain does it work ok?

I am assuming it is a factory radio, & just let her know, the poor thing has done it's time....it outlasted the tires the car came with, the vehicle warranty, it even saw y2k, so it is time to lay it to rest & get this neat new one we have with all these cool features (bling off the tooth)

Does she ave an old battery where cranking voltage goes low? that may be the cause, as when RS the dash lights are on , so radio lights are lit, & low voltage on old parts=little puffs of smoke

or perhaps installer got ign. & acc wires backward, so radio is on while actually cranking in RS?

sell her a new radio, install it for free, but charge more than usual on the kit harness & antenna adapter ;)

The lights are non functional in, whether remote started or started with the key. Problem is she claims it happened immediately after the install. I politely tried to explain to her, using light bulbs as an example, that if some of the bulbs are burnt out, but the others still work, then the circuit, switches, connections etc still function and that the problem lies with the bulbs ( in this case the lighting for these radio buttons). I'm not sure if she is going to accept in anyway I explain  that this is not the problem of the remote start.