The software giant released last week the second service pack for Office 2007, which provides support for documents saved in the ODF 1.1 format.
However, Rob Weir, chief ODF architect at IBM posted a report on his blog saying SP2 had problems reading some ODF spreadsheets saved by OpenOffice.org and lost data by "silently stripping out formulas" from cells. The resulting spreadsheet displays "the last value that the cells had", said Weir.
Weir explained: "If the formulas are stripped, then this cell no longer updates, and will return the wrong value."
He added that with SP2, Excel--the Office suite's spreadsheet program--instead saves spreadsheet formulas into an Excel namespace. "This namespace is not what OpenOffice and other ODF applications use. It is not the ODF 1.2 namespace," said Weir.
Another blogger, who claimed to belong to the Oasis (Organization for the Advancement of Structured Information Standards) ODF technical committee, posted a report later, saying this move by Excel fragments ODF and locks users into using Microsoft's Office product.
He said the new namespace will make new worksheets only understood by Office 2007, "eliminating the possibility that any other existing application could be used to usefully read the document".
ODF 1.2 is hoped to fix spreadsheet issue
Microsoft's response to the issue has been to say that the problem lies in the ODF 1.1 standard, which does not include formula syntax.
Doug Mahugh, senior program manager on the Office interoperability team at Microsoft posted a response to Weir saying the issue was foreseeable because ODF's earlier specifications did not define spreadsheet support sufficiently--a point raised three years ago, he said.
"Because ODF 1.0 and 1.1 do not support formulas, all ODF spreadsheet implementations are application-dependent," said Mahugh.
Mahugh confirmed in his post that Excel preserves the old values in the cells when encountering unknown formulae, but asserted that this would allow regular office users to still read the spreadsheets. He added that IBM's Lotus Symphony spreadsheet software, which keeps and displays unrecognized formulae, would render spreadsheets unreadable to the novice user.
He said ODF 1.2, when ready, is likely to address this issue through a new Open Formula syntax. Mahugh noted that Microsoft chose not to support this version because it has not been passed as a standard by Oasis, yet.
"But we're not there yet; ODF 1.2 is not done, and not even ready for public review," he said.
Oliver Bell, regional technology officer, Microsoft Asia-Pacific said in a Web chat with ZDNet Asia the company is trying to balance the task of complying with standards, while ensuring its products work with documents from older versions of Office.
"We want our ODF implementation to work and be interoperable. We also want to conform to the standard," he said.
Bell alluded to the issue being application-dependent as well: "Today, the only way to do that is to fully understand what every ODF implementation has chosen to do, and compensate for that.
"It is a multiple-step journey. Today, anybody can open and understand those documents. With [ODF] 1.2 the formulae become interoperable as well, and we all get to where we want to be."