I've replicated it:
1. Delete all 4 default audio view schemes (Artist/Album, Disk Location, File Type, Play Stats), leaving only Podcasts and Web Media
2. Close MC
3. Upon launch, the Podcasts and Web Media items are no longer in the menu.
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Media Center Registered 11.1.90 -- C:\Program Files\J River\Media Center 11\
Microsoft Windows XP Workstation 5.1 Service Pack 2 (Build 2600)
Intel Pentium 4 3191 MHz MMX / Memory: Total - 1572 MB, Free - 974 MB
Internet Explorer: 6.0.2900.2180 / ComCtl32.dll: 5.82.2900 / Shlwapi.dll: 6.0.2900 / Shell32.dll: 6.0.2900 / wnaspi32.dll: N/A
Ripping / Drive K: Mode:Normal Type:Auto Speed:Max
Digital playback: Yes / Use YADB: Yes / Get cover art: Yes / Calc replay gain: Yes / Copy volume: 32767
Eject after ripping: Yes / Play sound after ripping: No
Burning / Drive K: PIONEER DVD RW DVR-108 Addr: 0:1:0 Speed:16 MaxSpeed:32 BurnProof:Yes
Test mode: No / Eject after writing: Yes / Direct decoding: Yes / Write CD-Text: Yes
Use playback settings: No /