How about giving us some of your PC specs? Have you turned off any programs that might be interupting playback? Do you have a firewire camera that you could use to check playback?
I did test with a JVC GY-HD200U and there weren't any performance issues which led me back to the PC or other on the PC.
The system is running Windows 7, 64 bit with CS5 Production Premium following an upgrade from the CS4 version.
I've got 12 GB of Ram, (2) Intel Xeon Quad Core E5560 -2.8 GHZ processoCrs.
(1) 500GB SATA2 hard drive, 7200 RPM, 32 MC (System Drive)
(3) 1 TB SATA2 Hard drives, 7200 RPM, 32 MC (3 TB, RAID0 Storage Drive)
Nvidia GeForce 9800GT graphics Card
Supermicro X8DAi motherboard, Intel 5520 Chipset, 2-PCIe X16, 1 PCIe x4, 3-PCI, 10-USB2 ports, 2-pro/1000 NIC, 8-channel HD audio, 6 SATA ports, RAID 0/1/5/10
I've got the legacy drivers for the firewire card. I've checked to make sure all of the power save options are off along with all screen saver options. I've cleaned my Adobe Cache out, deleted my Adobe Preferences, went from the 4pin/6pin cable to a 6pin/6pin cable to feed the ADVC-700 from the PC, reset the ADVC 700 back to factory specs...all of this with no luck.
The problem seems to be worse since the move from CS4 to CS5 but it's hard to tell.
I've also hooked up an older ADVC-500 unit with the same output results.
I think I noted in the first post that this is happening on two indentical systems with the same cabling and programs and the same ADVC-700 boxes.
I've been told by Adobe to clean my C; drive and reload the OS and Adobe CS5 as I should have done that when I upgraded instead of just upgrading the system from CS4 to CS5 using the discs. I haven't done this yet as I have to budget time/workflow to accomodate.