No need to do any of that. EPG cache and epg.dat can be cleared from the GUI. No restart needed.I have had exactly the same issues as above and followed Mickeyblueys advice as follows: It solved completely my issues.
Use DCC to do this operation.
Kill enigma through telnet - init 4
Ftp to box and delete you're epg.dat file (remember for most of you this file is on your USB stick)
Next telnet - init 3 , to restart enigma.
Now do a fresh epg download
Everything should now work as normal.
Thanks for the great advice!
Jonathan
menu -> setup -> system -> EPG -> Delete EPG