Is it just me? I love printing negatives developed in Pyrocat HD - the ones that come out that is.

However, I do have a high failure rate when using it.

I switched to using the glycol form. And that has helped some. Still. From one batch of film I process to the next, I can never be sure the negs will turn out. This morning, I ruined a whole Jobo 3010 drum of 4x5 negatives by one of the following possible reasons. (The negatives were ultra-thin and high contrasty).:

Developped at 69 or 68 F vs. 70F?
Fixed in TF4 fixer for 5 mins, vs 3min?
Inadequately mixed the A solution into my distilled water before adding B solution (I dumped A stock, then B stock into 500ml distilled water, THEN mixed)?
I aerated my 500ml distlled water too much in the process of bringing to temeperature (done before adding either pyrocat component)?

My stock Pyrocat is Brand new from PF, version mixed in glycol. It is not contaminated because a batch I ran after the 10 failed sheets came out perfectly.

The major changes I made with the second batch, which did turn out well - unlike my first batch - was to:

1 Insure I dissolved part A completely into my working developer before adding part B.
2 Insure I was working at or slightly above 70F, and not at 69 as my first batch.
3 Insure I fixed in TF4 for 3.5 mins, not 5 min as my first batch.
4 Be cognizant not to aerate my distilled water before adding the stock deveoper components.

Which of these do you feel did the trick, or was it possibly none of the above?