Until a patch comes out that properly prevents this from happening, here is my current fix/workaround for the problem I previously posted, in which my Vehicle Delivery homie option on the phone would become permanently unavailable, even if I'd quit the game and reload. I didn't figure out any of this. Some random user on the official Saints Row 3 community message board worked this thing out pretty much by himself. You'd think they'd have Volition support people reading that thing considering there are dedicated sections for technical issues, but no. Anyway.
First up, get a hex editor. I used one called HxD. Next, find your savegame files. They're stored in a strange spot within your Steam folder: \userdata\[your Steam ID number]\55230\remote. The savegame names will start with "sr3save_00.sr3s_pc" and increment from there. Make backup copies of these just to be safe. I didn't need to revert back, but you want a safety net in case things don't work.
Open your save in the hex editor. Now goto offset 4330 in hexadecimal. It'll look something like this:
Code:
Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
---------------------------------------------------------
00004330 01 00 00 00 44 05 EE 36 05 00 00 00 41 0E 85 B7
00004340 01 00 00 00 A7 D8 22 B6 08 00 00 00 A8 41 41 84
00004350 01 00 00 00 BF 38 27 BE 00 00 00 00 F9 B1 BD 6E
00004360 00 00 00 00 7A F8 D1 C2 00 00 00 00 2A C2 69 FD
00004370 00 00 00 00 7A 4F 2A 9E 00 00 00 00 08 BE D4 E9
00004380 01 00 00 00 6C 6B B4 70 00 00 00 00 25 58 6B 50
00004390 00 00 00 00 B5 71 B7 9F 00 00 00 00 B9 E7 8A 86
000043A0 00 00 00 00 25 68 56 8C 00 00 00 00 70 2B A8 4D
000043B0 06 00 00 00 D7 65 CD BB 00 00 00 00 06 4E 2E 8D
000043C0 00 00 00 00 EA 13 14 11 00 00 00 00 D9 22 48 26
000043D0 00 00 00 00 4A E7 16 FE 06 00 00 00 49 10 FF B7
000043E0 00 00 00 00 DE BC C0 7E 00 00 00 00 B3 05 D4 C0
We are only going to look at the contents of two columns: 00 and 08.
The different values correspond to different statuses of the phone entries, with each offset row presumably representing a specific homie. For the sake of this fix, all that matters is that "01" means "is listed on your phone and not greyed out." Whether they'd be busy or not is another matter, presumably controlled by where you are in the story.
00 means "not being displayed at all" which would be the case if you didn't unlock something yet. I opted to just leave those untouched. Whether changing them to 01 would unlock things early is not something I care to delve into. Other numbers presumably refer to cooldown timers. From what I gather, once you call a homie, it sets the status value to 06, greys itself out and then counts back down to 01 at which point you can call them again. For whatever reason, it seems there are occasions where values greater than 06 get put in these fields, which amount to them just being grayed out forever even if you reload.
Solution? As long as there was a value other than "00" in either column 00 or 08 that was greater than "06", I changed it to a "01". In the case of my savegame listed above, there was only one single such value: the 08 over there in 4340 offset column 8. I saved the changes, loaded the game, and presto: I could once again have my Manapult delivered right to me for those times when I needed to quickly get on top of a building to collect drug pallets.
No idea if the problem will reoccur, but that's how I fixed it. Looks like nobody else was having that problem here anyway!