bam-bam doesn't post locked maps anyway you can check if the .img is ok looking at its details in GmapTool:
[Only registered and activated users can see links. ]

See here for map naming and paths:
[Only registered and activated users can see links. ]
Nuvi internal (diagnostic utility) OS map naming
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7x0/7x5
1. PROM1 = gmapprom.img
2. PROM2 = gmapprom1.img
3. Suppmap1 = gmapsupp.img (nuvi drive only)
4. Suppmap = gmapsupp.img (SD Card drive only)
5. Dir DB = gmapoem.img
6. Basemap = gmapbmap.img
Remove any .unl or .gma files, remove (after backing up all on pc) any .img covering the same area.

PS: "Garmin", not "garmin"