I had the same issue. My WD 750GB HDD MyBook essentials (plug powered 3.5', and connected to usb port 0 of Wii) suddenly* took up about 2 to 3 minutes to get in game. In some games like CoD MW3 and CoD BO online multiplayer modes, it lagged like CRAZY on IOS 250.
I reformatted the drive to FAT32 with 32kb clusters, and now it is back in full force. It boots about 31 seconds to play a game in usb loader GX from power up and 37 seconds if i let a dvd in the drive (for Dios Mios games like 1080, Sonic Collection, Midway Arcade Treasures, XIII etc).
Oh, and i now use IOS 223 for the CoD online modes in MW3 & BO, lags very very little, if at all.
By comparison, a 2.5' HDD, usb-powered Intenso 750GB i have, takes about 30 seconds to get in game from gx when powered on. It also never lags in Wii CoD online games. Unfortunately it is not compatible with Dios Mios (i'll try a Y cable in the future) so i had to fix the old WD HDD again.
*drive was constantly moved back and forth by from the Wii to the PC, to add games and movies, and one time it fell on the floor. Lesson learned, now i added everything i ever wanted to the HDD and i leave it well alone by the Wii at all times. Got a 64GB HCSD for movies.
TL;DR
Back up & format your HDD
I reformatted the drive to FAT32 with 32kb clusters, and now it is back in full force. It boots about 31 seconds to play a game in usb loader GX from power up and 37 seconds if i let a dvd in the drive (for Dios Mios games like 1080, Sonic Collection, Midway Arcade Treasures, XIII etc).
Oh, and i now use IOS 223 for the CoD online modes in MW3 & BO, lags very very little, if at all.
By comparison, a 2.5' HDD, usb-powered Intenso 750GB i have, takes about 30 seconds to get in game from gx when powered on. It also never lags in Wii CoD online games. Unfortunately it is not compatible with Dios Mios (i'll try a Y cable in the future) so i had to fix the old WD HDD again.
*drive was constantly moved back and forth by from the Wii to the PC, to add games and movies, and one time it fell on the floor. Lesson learned, now i added everything i ever wanted to the HDD and i leave it well alone by the Wii at all times. Got a 64GB HCSD for movies.
TL;DR
Back up & format your HDD