Try taking the breakout cable off, and then reseating it, sometimes this can fix issues.
if that doesn't help, try swapping the PCI card your Delta 1010LT is in. This is also known to sometimes help.
If that doesn't help, take the card out of your computer, and clean it with a soft bristle toothbrush. Sometimes dust connects around contacts and can cause a short which sometimes can create problems just like what you're describing.
How old is the card?
Core 2 Quad Q9400-Scythe Ninja Rev A|MSI Neo P45|WD 150GB Raptor|WD 250gb SATA-I|8GB G-Skill DDR2|WD Blue 640GB SATA-II|Logitech KB|Apple Mighty Mouse|ATI HD4850 512MB-Accelero S1|M-Audio 2x Delta 1010|Delta 66 Omni I/O|Corsair 400W|Cooler Master Elite 330
Dual Boot: Ubuntu 10.04 x64 Lucid/Windows 7 Home Premium x64
Adobe Audition Mac & PC, Logic Pro, Ardour, PT 9, Reaper x86 & x64, Ableton Live Lite
2x Delta 1010, 2x Delta 66, AP2496, FW Solo, Pulsar II, ProFire 2626, Fast Track C400